HSG.SRT.C.8: Solving Right Triangles in Applied Problems
In plain English: HSG.SRT.C.8 is the Common Core geometry standard that asks students to solve right triangles in real situations using sine, cosine, tangent and the Pythagorean Theorem. Students model ladders, ramps, shadows, and angles of elevation and depression with a right triangle, find the missing sides and angles, and interpret the answers. It is a modeling standard, usually taught in Geometry.
Use trigonometric ratios and the Pythagorean Theorem to solve right triangles in applied problems.
Common Core State Standards for Mathematics · Domain: Similarity, Right Triangles, and Trigonometry (SRT) · Cluster: Define trigonometric ratios and solve problems involving right triangles Also written as HSG-SRT.C.8 or G-SRT.8 · Official standard
Students solve applied right-triangle problems by choosing between the Pythagorean Theorem and the trigonometric ratios. Each problem starts from a real situation: a ladder against a wall, the height of a building, a boat seen from a lighthouse, a wheelchair ramp. Students draw a labeled right triangle, decide which relationship connects the known and unknown quantities, solve, and interpret the result in context.
The lesson introduces angles of elevation and depression and uses inverse ratios to find angles from side lengths. Students learn to solve the whole triangle (every side and angle), to check answers against the Pythagorean Theorem and the 90° angle sum, and to round sensibly for the situation.
Learning Objectives
By the end of this lesson, students will be able to:
Model an applied situation with a labeled right triangle, including angles of elevation and depression
Choose the Pythagorean Theorem, a trigonometric ratio or an inverse ratio based on what is known and what is asked
Find unknown side lengths and angle measures and solve the whole right triangle
Check answers with the Pythagorean Theorem and the angle sum, and interpret them with units and sensible rounding
Prior Knowledge Required
Students should already be comfortable with:
The Pythagorean Theorem in two dimensions 8.G.B.7
Definitions of sine, cosine and tangent for acute angles HSG.SRT.C.6
The sine and cosine of complementary angles HSG.SRT.C.7
Alternate interior angles formed by parallel lines 8.G.A.5
Solving one-step equations with the unknown in the numerator or the denominator
Show a photo or sketch of a ladder leaning against a house. Tell students the ladder is 20 feet long and its base is 5 feet from the wall.
Warm-Up Prompt
"How high up the wall does the ladder reach? What angle does it make with the ground? Which of these two questions can you answer with the Pythagorean Theorem alone, and which needs something else?"
Most students can find the height with the Pythagorean Theorem: h = √(400 - 25) = √375 ≈ 19.4 ft. The angle needs a trigonometric ratio: cos θ = 5/20, so θ ≈ 75.5°. Mention that ladder safety guides commonly recommend about one foot out for every four feet up, which gives an angle near 75°. Diagram 2 shows this triangle to scale. Use the two questions to frame the lesson: the Pythagorean Theorem connects three sides, and trigonometric ratios connect sides with angles.
Direct Instruction20 minutes
A four-step routine for applied right-triangle problems. Model it on every example:
Draw and label: sketch the situation, mark the right angle, and label the known sides and angles with units.
Choose the tool: three sides with one unknown, use the Pythagorean Theorem. A side and an acute angle, use sine, cosine or tangent. Two sides and an unknown angle, use an inverse ratio such as tan⁻¹.
Write and solve an equation: for example tan 38° = h/150, so h = 150 tan 38°. Keep full calculator precision until the end.
Check and interpret: the hypotenuse must be the longest side, the acute angles must add to 90°, and the answer must make sense in the situation, with units and sensible rounding.
Use Diagram 1 to define angle of elevation (measured up from the horizontal) and angle of depression (measured down from the horizontal). Because the horizontal line at the observer is parallel to the ground, the two angles are congruent alternate interior angles, so the angle of depression can be placed inside the right triangle at the far end. Remind students to check that calculators are in degree mode.
Pythagorean Theorem and an inverse ratio
A 20-foot ladder has its base 5 feet from a wall. Find the height it reaches and its angle with the ground.
Equation: h = √(20² - 5²) ≈ 19.4 ft; cos θ = 5/20, θ ≈ 75.5°
Angle of elevation
From a point 150 feet from the base of a building on level ground, the angle of elevation to the roof is 38°. How tall is the building?
Equation: tan 38° = h/150, so h = 150 tan 38° ≈ 117.2 ft
Angle of depression
From a lighthouse window 32 m above the sea, the angle of depression to a boat is 9°. How far is the boat from the base of the lighthouse?
Equation: tan 9° = 32/d, so d = 32/tan 9° ≈ 202.0 m
Finding an angle, then a side
An escalator carries riders 15 m along its incline and lifts them 7.5 m. Find its angle with the floor and the horizontal distance it covers.
Equation: sin θ = 7.5/15, θ = 30°; run = √(15² - 7.5²) ≈ 13.0 m
Solving the whole triangle
A kite string 250 ft long makes a 52° angle with level ground. Find the kite's height and its horizontal distance from the person holding it (ignore the person's height and any sag in the string).
Pairs solve three problems using the four-step routine. Each partner draws the sketch for one problem before either partner computes.
The sun is 41° above the horizon, and a tree casts an 18 m shadow on level ground. How tall is the tree? (18 tan 41° ≈ 15.6 m)
A 45-foot support cable runs from the top of a 36-foot pole to the ground. How far from the base of the pole is it anchored, and what angle does it make with the ground? (27 ft; sin⁻¹(36/45) ≈ 53.1°)
A small plane climbs at a steady 12° angle. How much altitude has it gained after covering 5 km of horizontal distance? (5 tan 12° ≈ 1.06 km)
After each problem, ask one pair to explain why they chose the ratio or theorem they used. Watch for students who use the cable length as a leg, and for students who round the angle before finding the side.
Independent Practice15-20 minutes
Students solve three problems alone and show a labeled sketch for each:
A delivery drone hovers 120 m above the ground, and the angle of depression from the drone to a landing pad is 35°. Find the horizontal distance to the pad and the straight-line distance from the drone to the pad.
A roof rises 6 inches for every 12 inches of horizontal run. Find the angle the roof makes with the horizontal and the length of a rafter that covers a 12-foot horizontal run.
A 65-inch television (measured on the diagonal) is 56.7 inches wide. Find its height and the angle its diagonal makes with the bottom edge.
Answers for the teacher: 171.4 m and 209.2 m; 26.6° and 13.4 ft; 31.8 in and 29.3°.
Closure10 minutes
Exit ticket: A playground slide is 4.2 m long and makes a 35° angle with the ground. (1) How high is the top of the slide? (2) How far from the ladder end does the slide reach along the ground? (3) Check your two answers with the Pythagorean Theorem. (Answers: about 2.4 m and 3.4 m; 2.41² + 3.44² ≈ 4.2².) Then ask students to write one sentence on how they chose between sine and cosine.
Differentiation Strategies
For Struggling Students
Provide a decision chart: "Do I know an angle? Is an angle asked for?" leading to the Pythagorean Theorem, a ratio or an inverse ratio
Give partly labeled sketches for the first problems, then only the words for later ones
Have students write the ratio with words first ("tan = opposite/adjacent") before substituting numbers
For Advanced Students
Pose two-triangle problems, such as finding a tower's height from two angles of elevation measured 30 m apart
Ask how much a 1° error in a clinometer reading changes the computed height of the school building in Activity 1
Have students design a ramp for a real doorway and justify it against the 1:12 maximum slope in U.S. accessibility guidelines
Assessment Guidance
What to Look For
Look first at the sketch: a correct, labeled right triangle usually leads to a correct answer. Check that students choose the tool from what is known, not from habit, and that they place the angle of depression correctly. Final answers should have units, reasonable rounding and a sentence of interpretation. Watch for calculators in radian mode (a ratio that does not fit the size of the angle is the usual sign) and for rounding an angle before using it to find a side.
02
Classroom Activities
3 Activities
1
Clinometer Field Measurement
25 minGroups of 3
Groups build a simple clinometer and use it to measure the height of a tall object on campus, such as a flagpole, a light pole or the school building, with an angle of elevation and a measured distance.
Build
Tape a drinking straw along the straight edge of a protractor
Tie a string through the protractor's center hole and hang a washer from it
When you sight the top of the object through the straw, the angle of elevation is 90° minus the protractor reading at the string
Procedure
One student measures a horizontal distance from the base of the object with a measuring tape
The sighter reads the angle while a partner records it; repeat three times and average
Measure the sighter's eye height and add it to the computed height
Sample data: distance 20 m, angle 34°, eye height 1.5 m, so the height is 20 tan 34° + 1.5 ≈ 15.0 m
Discussion Questions
Why must you add the eye height?
Which measurement do you trust least, and how could you improve it?
Two groups measured from different distances. Should their angles match? Should their heights?
Modification for Distance Learning
Students use a free phone clinometer app or a printed protractor at home to measure a door frame or a tall piece of furniture, then check their result with a tape measure.
2
Choose Your Tool Stations
20 minPairs rotating through 6 stations
Six station cards each describe a short applied problem. At each station, pairs first name the tool (Pythagorean Theorem, sine, cosine, tangent or an inverse ratio) and write the equation, then solve.
Station Cards
Station 1: A rectangular gate is 1.2 m wide and 1.6 m tall. How long is a diagonal brace? (Pythagorean Theorem: 2.0 m)
Station 2: A 6 m guy rope runs from the top of a tent pole to the ground at 50°. How tall is the pole? (sine: about 4.6 m)
Station 3: A 3 m loading ramp makes an 18° angle with the ground. How far does it reach horizontally? (cosine: about 2.85 m)
Station 4: The sun is 55° above the horizon. How long is the shadow of a 30 m building? (tangent: about 21.0 m)
Station 5: A road sign warns of an 8% grade, a rise of 8 m per 100 m of horizontal run. What angle does the road make with the horizontal? (inverse tangent: about 4.6°)
Station 6: A 5.5 m ladder has its base 1.4 m from a wall. What angle does it make with the ground? (inverse cosine: about 75.3°)
Procedure
Pairs spend about 3 minutes at each station
Before solving, pairs write the tool and the equation on the station's tally sheet
At the end, the class compares tallies and discusses any station where pairs chose different tools
Challenge Variation
Pairs write a seventh station card whose problem needs two tools, for example an inverse ratio followed by the Pythagorean Theorem, and trade it with another pair.
3
Design an Accessible Ramp
20 minGroups of 3-4
Groups design a wheelchair ramp for an entrance whose floor is 24 inches above the sidewalk. U.S. accessibility guidelines allow a slope of at most 1:12, meaning at least 12 inches of horizontal run for every inch of rise.
Tasks
Find the minimum horizontal run: 24 × 12 = 288 in, or 24 ft
Find the length of the ramp surface with the Pythagorean Theorem: √(24² + 288²) ≈ 289.0 in, about 24.1 ft
Find the ramp's angle with the ground: tan⁻¹(1/12) ≈ 4.8°
The entrance has only 20 ft of straight space in front of it. Explain why a single straight ramp will not fit and sketch a design with a turn
Procedure
Groups draw a labeled side view to scale on grid paper
Each group presents its design and its three computed values
The class compares the ramp angle with the angles of stairs and escalators from the lesson
Discussion Questions
Why is the ramp surface only slightly longer than the horizontal run?
Why do accessibility guidelines use a rise-to-run ratio instead of an angle?
03
Diagrams & Visual Aids
2 diagrams
Diagram 1: Angles of Elevation and Depression
An observer high above the ground looks down at a boat. The angle of depression is measured down from the horizontal line at the observer, and the angle of elevation is measured up from the ground at the boat. The two horizontal lines are parallel, so the angles are congruent and either one can be used inside the right triangle.
Diagram 2: Solving the Ladder Triangle
The warm-up ladder drawn to scale: a 20 ft ladder with its base 5 ft from the wall. The Pythagorean Theorem gives the height, and the cosine ratio with an inverse gives the angle with the ground. Together they solve the whole triangle.
04
Homework Assignment
~30 min
HSG.SRT.C.8 Homework: Right Triangles in Applied Problems
Directions: For every problem, draw and label a right triangle, name the tool you use (Pythagorean Theorem, a trigonometric ratio or an inverse ratio), and write the equation before solving. Round lengths to the nearest tenth and angles to the nearest tenth of a degree, and give units. You may use a calculator in degree mode.
Part 1: One Unknown at a Time (Problems 1-3)
A 28-foot extension ladder reaches 26.5 feet up a vertical wall. How far is the base of the ladder from the wall, and what angle does the ladder make with the ground?
A hiker stands on level ground 400 m from the base of a vertical cliff. The angle of elevation to the top of the cliff is 27°. How tall is the cliff?
From an observation deck 60 m above level ground, the angle of depression to a parked car is 14°. How far is the car from the point on the ground directly below the deck?
Part 2: Solving the Whole Triangle (Problems 4-5)
A straight road climbs 150 m over a horizontal distance of 2.4 km. Find the angle the road makes with the horizontal and the length of the road surface in meters.
A zip line is 85 m long and its far end is 12 m lower than its start. Find the angle of depression of the zip line and the horizontal distance it covers. Check your answers with the Pythagorean Theorem.
Part 3: Two Triangles (Problem 6)
From a point on level ground, the angle of elevation to the top of a tower is 50°. From a point 30 m farther away, in line with the first point and the tower, the angle of elevation is 35°. Find the height of the tower. (Hint: call the distance from the first point to the tower d and write two tangent equations.)
Rubric
Criterion
Full Credit (2 pts)
Partial Credit (1 pt)
No Credit (0 pts)
Model
Correct labeled right triangle with the given angle in the right place
Triangle drawn with one label or angle misplaced
No sketch or wrong triangle
Tool and Equation
Correct tool named and equation written for every problem
Correct tools with a missing equation
Wrong tool or no equation
Accuracy
All answers correct with units and sensible rounding
Most answers correct or units missing
Most answers incorrect
Check and Interpretation
Answers checked (Pythagorean Theorem or angle sum) and explained in context
Some checking or interpretation
None
05
Quiz: 20 Questions
Interactive, with answers
Instructions
Work through the questions in order. Your score updates as you answer, and Reset quiz clears everything so you or your students can try again.
Multiple choice: pick an option to check it. Short answer: write your answer, then reveal the model answer.
0 of 20 answered · 0 correct
Question 1 of 20 · Multiple Choice
In an applied right-triangle problem you know the hypotenuse and the leg opposite an unknown angle. Which tool finds that angle?
Answer: D
Opposite over hypotenuse is the sine, and an inverse ratio turns a ratio into an angle: θ = sin⁻¹(opposite/hypotenuse). Choice B finds the third side, not an angle. Choices A and C would need the angle to be known already.
Question 2 of 20 · Multiple Choice
A 15-foot ladder leans against a vertical wall with its base 4 feet from the wall. About how high up the wall does it reach?
Answer: B
h = √(15² - 4²) = √209 ≈ 14.5 ft. Choice A adds the squares instead of subtracting, which would make the ladder a leg. Choice C subtracts the lengths, and choice D adds them.
Question 3 of 20 · Multiple Choice
From a point 26 m from the base of a tree on level ground, the angle of elevation to the top of the tree is 40°. About how tall is the tree?
Answer: A
The height is opposite the 40° angle and 26 m is adjacent: h = 26 tan 40° ≈ 21.8 m. Choice B uses sine, which would treat 26 m as the hypotenuse. Choice C uses cosine. Choice D divides by tan 40° instead of multiplying.
Question 4 of 20 · Multiple Choice
A plane flying at an altitude of 2,000 feet sees the start of a runway at an angle of depression of 8°. About how far is the plane, measured horizontally, from the start of the runway?
Answer: C
The angle of elevation from the runway is also 8°, the altitude is opposite and the horizontal distance d is adjacent: tan 8° = 2000/d, so d = 2000/tan 8° ≈ 14,231 ft. Choice A multiplies by tan 8°. Choice B is 2000/sin 8°, the straight-line distance, not the horizontal one.
Question 5 of 20 · Multiple Choice
A ramp rises 2 feet over a horizontal run of 20 feet. About what angle does it make with the ground?
Answer: B
tan θ = 2/20 = 0.1, so θ = tan⁻¹(0.1) ≈ 5.7°. Choice A is the other acute angle of the triangle. Choice C gives the ratio instead of the angle. Choice D divides 20 by 2.
Question 6 of 20 · Multiple Choice
A soccer field is 100 m long and 64 m wide. About how far does a player run going straight from one corner to the opposite corner?
Answer: D
The diagonal is the hypotenuse: √(100² + 64²) = √14096 ≈ 118.7 m. Choice A adds the sides. Choice B subtracts the squares, which treats 100 m as the hypotenuse.
Question 7 of 20 · Multiple Choice
A kite string is 120 m long and makes a 48° angle with level ground. Ignoring sag, about how high is the kite?
Answer: A
The string is the hypotenuse and the height is opposite the 48° angle: h = 120 sin 48° ≈ 89.2 m. Choice B uses cosine, which gives the horizontal distance. Choice C uses tangent. Choice D divides by sin 48°.
Question 8 of 20 · Multiple Choice
Why is the angle of depression from an observer to an object equal to the angle of elevation from the object back to the observer?
Answer: C
The horizontal line at the observer and the ground are parallel, and the line of sight is a transversal, so the two angles are congruent alternate interior angles. Choice B is false: the line of sight is slanted. Choice D is true but does not explain why these two angles match.
Question 9 of 20 · Multiple Choice
A ramp of unknown length x makes a 35° angle with the ground and covers 12 m horizontally. Which equation gives x?
Answer: B
The ramp is the hypotenuse and 12 m is adjacent to the 35° angle: cos 35° = 12/x, so x = 12/cos 35° ≈ 14.6 m. Choice A multiplies instead of dividing, which would make the hypotenuse shorter than a leg. Choice D uses the wrong ratio.
Question 10 of 20 · Multiple Choice
A support wire is attached 40 feet up a vertical pole and anchored 18 feet from the base of the pole on level ground. About how long is the wire?
Answer: D
The wire is the hypotenuse: √(40² + 18²) = √1924 ≈ 43.9 ft. Choice B subtracts the squares. Choice A adds the lengths.
Question 11 of 20 · Multiple Choice
For the support wire in the previous question (40 feet up, 18 feet out), about what angle does the wire make with the ground?
Answer: A
At the anchor, 40 ft is opposite and 18 ft is adjacent: tan θ = 40/18, so θ = tan⁻¹(40/18) ≈ 65.8°. Choice B is the angle between the wire and the pole. Choice C is the ratio 40/18, not an angle.
Question 12 of 20 · Multiple Choice
In right △ABC, ∠C = 90°, m∠A = 62° and AB = 18 cm. About how long is BC?
Answer: C
BC is opposite ∠A and AB is the hypotenuse, so BC = 18 sin 62° ≈ 15.9 cm. Choice A uses cosine, which gives AC. Choice B uses tangent. Choice D divides by sin 62°, which would make a leg longer than the hypotenuse.
Question 13 of 20 · Multiple Choice
A 12-foot ladder makes a 70° angle with level ground. A student finds the height it reaches as 12 cos 70° ≈ 4.1 ft. What is wrong?
Answer: D
The ladder is the hypotenuse and the height is the leg opposite the 70° angle, so sine is needed. The student's 4.1 ft is the distance from the wall. A quick check also helps: a ladder at 70° is steep, so the height should be close to the ladder length.
Question 14 of 20 · Multiple Choice
A student computes tan 35 on a calculator and gets 0.4738. What happened?
Answer: B
tan(35 radians) ≈ 0.4738, while tan 35° ≈ 0.7002. Switching to degree mode fixes it. Choice C is wrong because tan⁻¹ turns a ratio into an angle, not an angle into a ratio.
Question 15 of 20 · Short Answer
A building entrance is 30 inches above the sidewalk. U.S. accessibility guidelines allow a ramp slope of at most 1:12. Find the minimum horizontal run of a straight ramp, in feet, and the length of the ramp surface.
Minimum run = 30 × 12 = 360 in = 30 ft. Ramp surface = √(30² + 360²) = √130500 ≈ 361.2 in, about 30.1 ft. The surface is only a little longer than the run because the slope is gentle.
Question 16 of 20 · Short Answer
From the roof of a 45 m building, the angle of depression to a bus stop is 22°. A second bus stop, farther away along the same straight road, has an angle of depression of 13°. How far apart are the two stops?
For each stop, tan(angle) = 45/(horizontal distance). Near stop: 45/tan 22° ≈ 111.4 m. Far stop: 45/tan 13° ≈ 194.9 m. The stops are about 83.5 m apart (subtract before rounding: 194.92 - 111.38 ≈ 83.5).
Question 17 of 20 · Short Answer
A sail is a right triangle. Its bottom edge is 3.2 m and its vertical edge is 7.5 m. Find the length of the third edge and both acute angles.
Third edge (the hypotenuse) = √(3.2² + 7.5²) = √66.49 ≈ 8.2 m. The angle at the bottom corner away from the mast is tan⁻¹(7.5/3.2) ≈ 66.9°, and the angle at the top is 90° - 66.9° ≈ 23.1°.
Question 18 of 20 · Short Answer
After takeoff, a plane climbs in a straight line at 15° above the horizontal. After it has flown 3,000 m along that line, what is its altitude, and how far has it traveled horizontally? Check with the Pythagorean Theorem.
Altitude = 3000 sin 15° ≈ 776.5 m. Horizontal distance = 3000 cos 15° ≈ 2,897.8 m. Check: 776.5² + 2897.8² ≈ 9,000,197, and 3000² = 9,000,000; the small difference comes from rounding.
Question 19 of 20 · Short Answer
For each situation, name the tool you would use and explain why: (a) you know both legs and want the hypotenuse; (b) you know an acute angle and the hypotenuse and want the opposite leg; (c) you know both legs and want an acute angle.
(a) Pythagorean Theorem: it connects three sides, and no angle is involved. (b) Sine: sin θ = opposite/hypotenuse links the known angle, the known side and the unknown side. (c) Inverse tangent: tan θ = opposite/adjacent, and tan⁻¹ turns that ratio into the angle.
Question 20 of 20 · Short Answer
A surveyor stands 50 m from the base of a tree on level ground. Her instrument, 1.6 m above the ground, measures a 32° angle of elevation to the top of the tree. How tall is the tree?
The tangent gives the height above the instrument: 50 tan 32° ≈ 31.2 m. Add the instrument height: 31.2 + 1.6 ≈ 32.8 m. Forgetting the 1.6 m is a common error in this kind of problem.
0 of 20 answered · 0 correct
06
Frequently Asked Questions
10 Questions
What does HSG.SRT.C.8 mean?
HSG.SRT.C.8 means students use sine, cosine, tangent and the Pythagorean Theorem to find unknown sides and angles of right triangles in real situations. Typical problems involve ladders, ramps, shadows, and angles of elevation and depression. Students must set up the triangle from the situation, solve it and interpret the answer.
Is HSG.SRT.C.8 a Geometry standard?
Yes. It is usually taught in Geometry, after the trigonometric ratios are defined (HSG.SRT.C.6). Common Core also marks it as a modeling standard, so students are expected to turn a real situation into a right triangle, not only work with a triangle that is already drawn.
What does it mean to "solve a right triangle"?
It means finding every unknown side length and angle measure. Starting from two sides, or one side and one acute angle, students can find all the rest with the Pythagorean Theorem, the trigonometric ratios and the fact that the acute angles add to 90°.
What is the difference between an angle of elevation and an angle of depression?
An angle of elevation is measured up from the horizontal to a line of sight; an angle of depression is measured down from the horizontal. When one person looks up at another who is looking down, the two angles are equal, because they are alternate interior angles between parallel horizontal lines.
When should students use the Pythagorean Theorem instead of trig?
Use the Pythagorean Theorem when the problem involves only the three sides: two are known and the third is asked for. As soon as an angle is known or asked for, a trigonometric ratio (or an inverse ratio for an unknown angle) is needed. Many problems use both, one after the other.
Do students need inverse trig functions for HSG.SRT.C.8?
Yes, to find an angle from two sides. On a calculator, sin⁻¹, cos⁻¹ and tan⁻¹ turn a ratio into an angle. Students do not need the inverse trigonometric functions as functions (that is a later topic), only as a calculator tool for angles in right triangles.
What mistakes do students make on right-triangle word problems?
Frequent errors include using a calculator in radian mode, placing the angle of depression at the wrong vertex, using the hypotenuse as a leg in the Pythagorean Theorem, forgetting an eye or instrument height, and rounding an angle before using it to find a side. A labeled sketch prevents most of them.
How is HSG.SRT.C.8 tested?
Typical items describe a situation in words and ask for a height, distance or angle, often with a diagram. Some ask students to choose the correct equation instead of computing. The digital SAT includes right-triangle problems of this kind in its Geometry and Trigonometry domain.
How precise should the answers be?
Keep full calculator precision during the work and round only the final answer, to a precision that fits the situation: a ladder height to the nearest tenth of a foot, a distance at sea to the nearest meter. Answers with no units, or with more decimal places than the measurements justify, should be revised.
Where is right-triangle trigonometry used outside school?
Surveyors, builders, roofers, pilots and engineers use it to find heights, distances and slopes they cannot measure directly. Ramp design is one example: U.S. accessibility guidelines limit ramp slope to 1:12, and students can compute the resulting run, ramp length and angle.
07
Related Standards
5 standards
These standards connect to HSG.SRT.C.8: prerequisites to review first, parallel standards at the same level, and next steps that build on it.
Before this lesson
8.G.B.7Prerequisite
Apply the Pythagorean Theorem to find unknown side lengths in right triangles
