7.G.B.5: Angle Relationships and Equations for Unknown Angles
In plain English: 7.G.B.5 is the Common Core grade 7 math standard that asks students to use facts about supplementary, complementary, vertical and adjacent angles to write and solve simple equations for an unknown angle in a figure. For example, two angles that form a straight line add to 180°, so (4x + 8) + 72 = 180 gives x = 25. Problems often take more than one step.
Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure.
Common Core State Standards for Mathematics · Domain: Geometry (G) · Cluster: Solve real-life and mathematical problems involving angle measure, area, surface area, and volume. Also written as 7.G.5 · Official standard
Students find unknown angles by reasoning, not by measuring. An angle is formed by two rays (straight paths that start at a point) with a shared endpoint called the vertex, and it is measured in degrees (°). The symbol ∠ABC names the angle whose vertex is the middle letter, B. Four facts do most of the work. Complementary angles add to 90°, the size of a right angle (a square corner), and each one is the complement of the other. Supplementary angles add to 180°, the size of a straight angle (a straight line), and each one is the supplement of the other. Adjacent angles share a vertex and a side and do not overlap, so their measures add up to the measure of the larger angle they make together. When two lines cross, the angles across from each other are vertical angles, and vertical angles are always equal.
Students use these facts to write an equation for an unknown angle and solve it, for example 2x + 34 = 90 for two adjacent angles that make a right angle. Many problems take more than one step: first use one fact to find an angle, then use another fact to reach the one you want. All equations here have the variable on one side only, in the forms from 7.EE.B.4. Figures on quizzes may not be drawn to scale, so students should trust the facts and not a protractor.
Learning Objectives
By the end of this lesson, students will be able to:
Identify supplementary, complementary, vertical and adjacent angles in a figure
Explain why vertical angles are equal, using supplementary angles
Write an equation for an unknown angle from a fact about angle pairs
Solve the equation and find every unknown angle in a figure, using more than one step when needed
Prior Knowledge Required
Students should already be comfortable with:
Adding angle measures: when an angle is split into parts, the parts add to the whole 4.MD.C.7
Solving equations of the form px + q = r and p(x + q) = r 7.EE.B.4
Combining like terms (terms with the same variable part), for example 3x + x = 4x 7.EE.A.1
Reading a protractor (a tool for measuring angles) and knowing that a right angle is 90° and a straight angle is 180°
Draw a straight line on the board with a ray coming out of a point on it, so the line is split into two angles. Label one of them 130°.
Warm-Up Prompt
"A straight line is split into two angles. One is 130°. How big is the other one, without a protractor? How do you know?"
Students should reason that a straight line makes a 180° angle, so the other angle is 180 - 130 = 50°. Ask a student to write this as an equation with a letter: x + 130 = 180. Then ask: "What if the two angles made a square corner instead?" (They would add to 90°.) Tell students that today they will name these angle pairs and write equations like this one for harder figures.
Direct Instruction20 minutes
Introduce the four angle words with a quick sketch for each, and keep them on the board:
Angle pair facts
Pair
What it means
Equation it gives
Adjacent angles
Share a vertex and a side, and do not overlap
The parts add to the whole angle
Complementary angles
Two angles whose measures add to 90°
angle 1 + angle 2 = 90
Supplementary angles
Two angles whose measures add to 180°
angle 1 + angle 2 = 180
Vertical angles
Across from each other where two lines cross
angle 1 = angle 2
Point out that one pair can have two names. Two adjacent angles that form a straight line are both adjacent and supplementary. Complementary or supplementary angles do not have to touch: a 30° angle in one corner of the room and a 60° angle in another are still complementary.
Why vertical angles are equal. In Diagram 1, the 65° angle and ∠2 form a straight line, so ∠2 = 115°. The angle across from the 65° angle also forms a straight line with ∠2, so it is 180 - 115 = 65° too. The same argument works for any two crossing lines, so vertical angles are always equal.
Work through the examples. For each one, students say which fact they use before they write the equation.
Supplementary adjacent angles
Two adjacent angles form a straight line. One measures (4x + 8)° and the other measures 72°. Find x and the unknown angle.
Equation: Angles on a straight line add to 180°: (4x + 8) + 72 = 180, so 4x + 80 = 180, 4x = 100 and x = 25. The angle is 4(25) + 8 = 108°. Check: 108 + 72 = 180.
Complementary adjacent angles
A ray splits a right angle into two adjacent angles of 34° and (2x)°. Find x.
Equation: The two angles add to 90°: 2x + 34 = 90, so 2x = 56 and x = 28. The unknown angle is 56°. See Diagram 2.
Vertical angles
Two lines cross. One angle measures 65°, and the angle across from it measures (5x - 15)°. Find x and the other two angles.
Equation: Vertical angles are equal: 5x - 15 = 65, so 5x = 80 and x = 16. Each of the other two angles forms a straight line with the 65° angle, so each is 180 - 65 = 115°. See Diagram 1.
Three adjacent angles on a line
Three adjacent angles form a straight line: 42°, x° and (2x)°. Find each unknown angle.
Equation: 42 + x + 2x = 180, so 3x + 42 = 180, 3x = 138 and x = 46. The angles are 46° and 92°. Check: 42 + 46 + 92 = 180.
Multi-step: supplementary, then vertical
Two lines cross. ∠1 measures 58°. ∠2 is next to ∠1 on the same line, and ∠3 is across from ∠2 and measures (x + 40)°. Find x.
Equation: Step 1: ∠1 and ∠2 form a straight line, so ∠2 = 180 - 58 = 122°. Step 2: ∠3 and ∠2 are vertical angles, so x + 40 = 122 and x = 82.
After Example 5, ask: "Could we find x in one step?" (Yes, because ∠3 and ∠1 also form a straight line: x + 40 + 58 = 180. Both routes give x = 82.) Show students that the order of the facts can change, but the answer stays the same.
Guided Practice15 minutes
Pairs solve these problems. Partner A names the fact and writes the equation, and Partner B solves and checks it by adding the angles. They switch roles for each problem.
Guided practice problems with answers
Problem
Answer
Find the complement of a 27° angle. Write an equation first.
x + 27 = 90, so x = 63°
Two adjacent angles form a straight line: (3x)° and (x + 20)°. Find both angles.
4x + 20 = 180, x = 40: the angles are 120° and 60°
Two lines cross. An angle of (2x + 14)° is across from an angle of 86°. Find x.
Vertical angles: 2x + 14 = 86, x = 36
Two rays split a right angle into three adjacent angles: 18°, x° and (2x)°. Find the two unknown angles.
3x + 18 = 90, x = 24: the angles are 24° and 48°
Listen for students who use 180 when the angles make a right angle, and for students who set vertical angles to add to 180 instead of setting them equal. Ask: "Does your answer look right in the picture? Is an angle that looks sharp less than 90°?"
Independent Practice15 minutes
Students solve six problems on their own. For each one they name the fact, write an equation, solve it and check by adding.
Independent practice problems with answers
Problem
Answer
Find the supplement of a 47° angle
133°
Find the complement of a 71° angle
19°
Adjacent angles (x + 35)° and 101° form a straight line. Find x.
x = 44
Vertical angles measure (3x - 6)° and 96°. Find x.
x = 34
Complementary angles measure (4x)° and (x + 15)°. Find both angles.
x = 15: 60° and 30°
Three adjacent angles form a straight line: x°, 64° and (x + 20)°. Find the unknown angles.
x = 48: 48° and 68°
Closure5 minutes
Exit ticket: (1) Two lines cross. One angle is (6x)°, and the angle across from it is 84°. Find x and all four angles. (Answer: 6x = 84, so x = 14. The angles are 84°, 96°, 84° and 96°.) (2) In one sentence, explain the difference between complementary and supplementary angles.
Differentiation Strategies
For Struggling Students
Give a fact card with a sketch of each pair and the equation it gives (the table from Direct Instruction)
Have students shade the angles in a pair with the same color before writing the equation
Start with problems that give a number for one angle before moving to two expressions
For Advanced Students
Ask students to explain in writing why vertical angles are always equal, for any two crossing lines
Give three lines that cross at one point and ask for all six angles when two of them are known
Ask students to write their own multi-step angle problem that needs two different facts, and trade with a partner
Assessment Guidance
What to Look For
Check that students name the fact (complementary, supplementary, vertical or adjacent) before writing each equation. Look for 90 in right-angle problems and 180 on straight lines, for vertical angles set equal, not added, and for a check that adds the angles back up. In multi-step problems, students should label the angle they find first.
02
Classroom Activities
3 Activities
1
Angle Pair Card Sort
15 minPairs
Pairs sort 8 cards that each describe a pair of angles. They write every name that fits the pair (a pair can have two names) and, where one angle is missing, find it.
Cards (answer key)
C1: A 35° angle and a 55° angle in different parts of a picture (complementary)
C2: A 120° angle and a 60° angle that share a side and form a straight line (adjacent and supplementary)
C3: Two angles across from each other where two lines cross; one is 75° (vertical: the other is 75°)
C4: A 25° angle and a 65° angle that share a side and fill a right angle (adjacent and complementary)
C5: A 140° angle and a 40° angle that do not touch (supplementary)
C6: A 30° angle and a 50° angle that share a vertex and a side (adjacent only: they make 80°)
C7: Two right angles side by side that form a straight line (adjacent and supplementary)
C8: Two angles across from each other where two lines cross; one is 110° (vertical: the other is 110°)
Discussion Questions
Which cards have two names? What do those pairs have in common?
Card C6 shows adjacent angles that are neither complementary nor supplementary. Why?
Can two vertical angles ever be adjacent? Explain.
Modification for Distance Learning
Put the 8 cards on a shared slide with four labeled boxes. Pairs drag each card into every box that fits, copying a card when it belongs in two boxes.
2
Fold, Measure, Predict
15 minPairs
Each student folds a sheet of paper twice so that two creases cross, then traces the creases with a pencil to form two crossing lines. Pairs measure the four angles with a protractor and look for the patterns behind the facts.
Procedure
Fold the paper once, unfold it, then fold it again so the second crease crosses the first at a slant
Trace both creases, then label the four angles ∠1, ∠2, ∠3 and ∠4 going around the crossing point
Measure ∠1 only, then predict the other three with the facts before measuring them
Record predicted and measured values in a table, and add all four measures
Sample Results (invented)
One student measured ∠1 = 52° and predicted ∠2 = 128°, ∠3 = 52° and ∠4 = 128°. The measured values were 53°, 127°, 52° and 128°, which add to 360°.
Discussion Questions
Why might a measured angle be 1° off from the prediction?
Which facts did you use to predict ∠2 and ∠3?
Why do the four angles always add to 360°?
Challenge Variation
Fold a third crease through the same crossing point. Measure two of the six angles and predict the other four.
3
Street Map Angles
20 minGroups of 3-4
Groups get four cards from an invented town map where streets and paths cross. For each card, they sketch the corner, name the fact, write an equation and solve it.
Map Cards (answer key)
M1: Main Street and First Avenue cross, and one corner angle is 68°. Find the other three. (112°, 68° and 112°)
M2: A bike path meets straight Main Street, making adjacent angles of (3x + 6)° and 81°. Find x. (3x + 87 = 180, x = 31, so the angle is 99°)
M3: A corner lot has a right-angle corner. A path splits it into angles of (x + 12)° and (2x)°. Find both angles. (3x + 12 = 90, x = 26: 38° and 52°)
M4: Oak Street and Pine Street cross. An angle of (4x - 20)° is across from an angle of 100°. Find x. (4x - 20 = 100, x = 30)
Discussion Questions
Which cards used 180 and which used 90? How could you tell from the map?
In M1, which angles did you find with the vertical angle fact, and which with the supplementary fact?
03
Diagrams & Visual Aids
2 diagrams
Diagram 1: Vertical and Adjacent Angles at Two Crossing Lines
Two lines cross. The shaded angles are vertical angles, so they are equal: 5x - 15 = 65 gives x = 16. Neighboring angles form a straight line, so each unshaded angle is 180° - 65° = 115°. The lines are drawn at the real angle of 65°.
Diagram 2: Complementary Angles and Adjacent Angles on a Line
Left: a ray splits a right angle into 34° and (2x)°, so 2x + 34 = 90 and x = 28. Right: two rays split a straight angle into 42°, x° and (2x)°, so 3x + 42 = 180 and x = 46. Every ray is drawn at its real angle.
04
Homework Assignment
~30 min
7.G.B.5 Homework: Finding Unknown Angles
Directions: For each problem, name the fact you use (supplementary, complementary, vertical or adjacent), write an equation, solve it, and check by adding the angles. Figures are described in words, so sketch each one first.
Part 1: Angle Pair Facts (Problems 1-2)
An angle measures 29°. (a) Find its complement. (b) Find its supplement. (c) Explain why the supplement is always 90° more than the complement.
Two adjacent angles form a straight line. One measures (5x + 10)° and the other measures 70°. Write and solve an equation for x, then find the unknown angle.
Part 2: Equations in Figures (Problems 3-4)
Two lines cross. One angle measures (7x - 4)°, and the angle across from it measures 87°. Find x. Then find the angle next to the 87° angle.
A ray splits a right angle into two adjacent angles of (3x + 6)° and 39°. Find x and the unknown angle.
Part 3: Multi-Step Problems (Problems 5-6)
Three adjacent angles form a straight line. They measure (2x)°, (3x)° and 55°. Find x and the two unknown angles.
Two straight roads cross. One of the angles between them is 4 times as large as the angle next to it. Write an equation, then find all four angles where the roads cross.
Rubric
Criterion
Full Credit (2 pts)
Partial Credit (1 pt)
No Credit (0 pts)
Naming the Fact
Correct fact named for every problem
One fact missing or wrong
Facts missing or wrong in several problems
Writing the Equation
Equation matches the fact and the figure
Equation has one error, such as 180 for 90
No equation, or it does not match
Solving and Checking
Correct x and angles, with a check by adding
Correct x but an angle missing, or no check
Most answers incorrect
05
Quiz: 20 Questions
Interactive, with answers
Instructions
Figures are described in words and are not drawn to scale, so sketch each one and use the angle facts. 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
Which pair of angle measures is complementary?
Answer: A
Complementary angles add to 90°, and 23 + 67 = 90. Choice B adds to 180°, so those angles are supplementary. Choice C adds to 100°. Choice D shows two equal angles, as vertical angles would be, but 67 + 67 = 134.
Question 2 of 20 · Multiple Choice
Two lines cross. What is always true about a pair of vertical angles?
Answer: C
Vertical angles are equal, because each one forms a straight line with the same neighboring angle. Choice A and choice B are true only for special pairs, not for every pair of vertical angles. Choice D describes adjacent angles; vertical angles share only the vertex.
Question 3 of 20 · Multiple Choice
∠PQR and ∠RQS share the vertex Q and the side QR, and they do not overlap. Which word must describe them?
Answer: B
Angles that share a vertex and a side without overlapping are adjacent. Choice C and choice D depend on the measures, which are not given, so they are not certain. Choice A is wrong because vertical angles do not share a side.
Question 4 of 20 · Multiple Choice
What is the supplement of a 64° angle?
Answer: D
Supplementary angles add to 180°: 180 - 64 = 116°. Choice A is the complement, 90 - 64. Choice B subtracts from 360 instead of 180. Choice C gives the same angle, which would be true only for vertical angles.
Question 5 of 20 · Multiple Choice
What is the complement of a 58° angle?
Answer: A
Complementary angles add to 90°: 90 - 58 = 32°. Choice B is the supplement, 180 - 58. Choice C adds 90 and 58 instead of subtracting. Choice D gives the same angle, as if the angles were vertical.
Question 6 of 20 · Multiple Choice
Two adjacent angles form a straight line. One measures (6x + 12)° and the other measures 78°. Which equation can you use to find x?
Answer: C
Angles that form a straight line are supplementary, so they add to 180°: 6x + 12 + 78 = 180 (then x = 15). Choice A sets them equal, which is the rule for vertical angles. Choice B uses 90°, the rule for complementary angles. Choice D uses 360°, the sum of all four angles around a point.
Question 7 of 20 · Multiple Choice
Two lines cross. An angle measures (4x - 10)°, and the angle across from it measures 70°. What is x?
Answer: B
The angles are vertical, so they are equal: 4x - 10 = 70. Add 10: 4x = 80. Divide by 4: x = 20. Choice A subtracts 10 instead of adding it (4x = 60). Choice C treats the angles as supplementary: 4x - 10 = 110, so 4x = 120. Choice D ignores the -10 and solves 4x = 70.
Question 8 of 20 · Multiple Choice
A ray splits a right angle into two adjacent angles. One measures (5x)° and the other measures 35°. What is x?
Answer: D
The angles fill a right angle, so 5x + 35 = 90. Subtract 35: 5x = 55, so x = 11. Choice A uses 180 instead of 90 (5x = 145). Choice B sets 5x equal to 35. Choice C adds 35 instead of subtracting it (5x = 125).
Question 9 of 20 · Multiple Choice
Three adjacent angles form a straight line: 38°, x° and (x + 12)°. What is x?
Answer: A
The three angles add to 180: 38 + x + x + 12 = 180, so 2x + 50 = 180, 2x = 130 and x = 65. Check: 38 + 65 + 77 = 180. Choice B forgets the 12 (2x + 38 = 180). Choice C uses 90 instead of 180 (2x + 50 = 90). Choice D stops at 2x = 130 and does not divide by 2.
Question 10 of 20 · Multiple Choice
Two lines cross. ∠1 measures 41°. ∠2 is next to ∠1 on the same line, and ∠3 is across from ∠2. What is the measure of ∠3?
Answer: C
∠1 and ∠2 form a straight line, so ∠2 = 180 - 41 = 139°. ∠3 and ∠2 are vertical angles, so ∠3 = 139°. Choice A is the angle across from ∠1, not from ∠2. Choice B uses 90 instead of 180. Choice D subtracts 41 from 360.
Question 11 of 20 · Multiple Choice
Two lines cross. An angle measures (3x + 15)°, and the angle across from it measures 105°. Which equation can you use to find x?
Answer: D
Angles across from each other are vertical angles, which are equal: 3x + 15 = 105 (so x = 30). Choice A treats them as supplementary, which is the rule for neighboring angles. Choice B adds 15 to 105 instead of subtracting it. Choice C adds two angles to 360, but only all four angles around the point add to 360.
Question 12 of 20 · Multiple Choice
A carpenter cuts across the square corner of a board, from the corner point, splitting the 90° corner into two adjacent angles. One angle is 40° and the other is (2x + 4)°. What is x?
Answer: B
The two angles make the 90° corner: 2x + 4 + 40 = 90, so 2x + 44 = 90, 2x = 46 and x = 23. Choice A uses 180 instead of 90 (2x = 136). Choice C sets 2x + 4 equal to 40. Choice D forgets the 4 (2x + 40 = 90).
Question 13 of 20 · Multiple Choice
Two adjacent angles form a straight line, and one is 3 times as large as the other. What is the smaller angle?
Answer: C
Let x be the smaller angle: x + 3x = 180, so 4x = 180 and x = 45°. The larger angle is 135°. Choice A uses 90 instead of 180 (4x = 90). Choice B divides 180 by 3 instead of by 4. Choice D is the larger angle.
Question 14 of 20 · Multiple Choice
Which statement is always true?
Answer: B
Two adjacent angles that together form a straight line make a straight angle, so they add to 180°. Choice A is false: adjacent angles can add to any amount, such as 30° + 50° = 80°. Choice C is false because vertical angles share only a vertex, not a side. Choice D is false: complementary angles only need to add to 90°, and they do not have to touch.
Question 15 of 20 · Short Answer
Two complementary angles measure (x + 14)° and (3x)°. Write an equation and find both angles.
Complementary angles add to 90: x + 14 + 3x = 90, so 4x + 14 = 90, 4x = 76 and x = 19. The angles are 33° and 57°. Check: 33 + 57 = 90.
Question 16 of 20 · Short Answer
Two lines cross. One angle measures (2x + 30)°, and the angle next to it measures 114°. Find x and all four angles.
Neighboring angles form a straight line: 2x + 30 + 114 = 180, so 2x = 36 and x = 18. That angle is 66°. The vertical angles give the other two: the four angles are 66°, 114°, 66° and 114°.
Question 17 of 20 · Short Answer
Three adjacent angles form a straight line: (x + 10)°, (2x)° and 50°. Find x and the two unknown angles.
x + 10 + 2x + 50 = 180, so 3x + 60 = 180, 3x = 120 and x = 40. The angles are 50° and 80°. Check: 50 + 80 + 50 = 180.
Question 18 of 20 · Short Answer
Two lines cross, and one of the angles is 143°. Explain how to find the other three angles without a protractor, and give their measures.
The angle across from the 143° angle is a vertical angle, so it is also 143°. Each angle next to the 143° angle forms a straight line with it, so it is 180 - 143 = 37°. The four angles are 143°, 37°, 143° and 37°, and they add to 360°.
Question 19 of 20 · Short Answer
Line AB and line CD cross at point E. Ray EF makes a right angle with line AB, so ∠AEF = 90°. Ray EC lies inside ∠AEF, and ∠CEF = 28°. Find ∠AEC and ∠DEB.
Step 1: ∠AEC and ∠CEF are adjacent and fill the right angle, so they are complementary: ∠AEC + 28 = 90 and ∠AEC = 62°. Step 2: ∠DEB is across from ∠AEC where lines AB and CD cross, so they are vertical angles: ∠DEB = 62°.
Question 20 of 20 · Short Answer
Two straight paths cross in a park. One angle between them is 15° more than twice the angle next to it. Find all four angles.
Let a be the smaller angle. Neighboring angles form a straight line: a + (2a + 15) = 180, so 3a + 15 = 180, 3a = 165 and a = 55. The larger angle is 2(55) + 15 = 125°. With vertical angles, the four angles are 55°, 125°, 55° and 125°.
0 of 20 answered · 0 correct
06
Frequently Asked Questions
10 Questions
What does 7.G.B.5 mean?
7.G.B.5 means students use four facts about angle pairs to write and solve equations for unknown angles. Complementary angles add to 90°, supplementary angles add to 180°, vertical angles are equal, and adjacent angles add to the angle they form together. A typical problem gives an angle as an expression such as (4x + 8)° and asks for x, often in more than one step.
What is the difference between complementary and supplementary angles?
Complementary angles add to 90°, and supplementary angles add to 180°. One way to remember: a right angle looks like a corner (90°, complementary), and a straight line is 180° (supplementary). The two angles in a pair do not have to touch.
Why are vertical angles always equal?
Because both of them form a straight line with the same neighboring angle. If two lines cross and one angle is 65°, its neighbor is 180 - 65 = 115°. The angle across from the 65° angle is also next to that 115° angle, so it is 180 - 115 = 65°. The argument works for any angle, so vertical angles are always equal.
What are adjacent angles?
Adjacent angles share a vertex and a side and do not overlap. Their measures add up to the angle they make together. They can be complementary (filling a right angle), supplementary (filling a straight line), or neither, such as a 30° angle and a 50° angle that make 80°.
Is 7.G.B.5 about measuring angles with a protractor?
No. The standard is about reasoning with angle facts and equations. Protractors are useful for exploring the facts, as in the folding activity, but test figures are often not drawn to scale. Students should find the answer from the facts and use the picture only to check that the answer makes sense.
What mistakes do students make on angle relationship problems?
A common mistake is using 180 when the angles fill a right angle, or 90 when they form a straight line. Other frequent errors are adding vertical angles to 180 instead of setting them equal, and stopping at x without finding the angle itself. Asking students to name the fact before writing the equation helps.
What grade is 7.G.B.5, and what comes next?
It is a grade 7 standard in the Geometry domain. In grade 8, students use informal arguments about the angles of triangles and the angles formed when parallel lines are crossed by another line (8.G.A.5). In high school Geometry, students prove that vertical angles are equal and other theorems about lines and angles (HSG.CO.C.9).
Does 7.G.B.5 include equations with the variable on both sides?
No. In grade 7 the equations are simple: the variable appears on one side, as in 2x + 34 = 90 or (4x + 8) + 72 = 180 after combining like terms. Problems such as vertical angles of (3x + 10)° and (5x - 20)° lead to variables on both sides, which students learn in grade 8 (8.EE.C.7).
What does "multi-step" mean in 7.G.B.5?
It means students may need more than one angle fact to reach the answer. For example, when two lines cross and ∠1 is 58°, students first use supplementary angles to find its neighbor, 122°, and then use vertical angles to find the angle across from that neighbor. Writing down each step with the fact it uses keeps the work clear.
How can parents help with 7.G.B.5 at home?
Parents can look for angle pairs in everyday objects. Open scissors show two crossing lines with vertical angles, a street corner shows a right angle, and a door hinge makes supplementary angles with the wall. Ask your child: "If this angle is 40°, what is the one next to it?" and have them explain which fact they used.
07
Related Standards
6 standards
These standards connect to 7.G.B.5: prerequisites to review first, parallel standards at the same level, and next steps that build on it.
Before this lesson
4.MD.C.7Prerequisite
Recognize angle measure as additive and solve for unknown angles in diagrams
Lesson coming soon
6.EE.B.7Prerequisite
Solve real-world problems with equations x + p = q and px = q for nonnegative rationals
