Course: 7th Grade Math DETAIL LESSON PLAN

Student Objective 7.G.5 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. Lesson 8.3.1 – Replacement Lesson Angles and Pairs of Angles Prior Knowledge Review bellwork Review homework

Anticipatory Set / Introduction

TODAY, we will use those skills to help us classify different types of angles.

“Angel” songs.

Say… As an introduction to today’s lesson I would like to play a few songs. Listen to the songs and tell me what they all have in common. Play pieces of songs that all mention the word “Angel”. Tell them not to shout out the answer because it may take some a few songs before they figure it out. When ready, call on a student or have students answer together,

They all deal with _________? Answer: They all deal with “Angels!”

Today, I have been inspired to title our lesson “The Angel of Angles”. Display, “The Angel of Angles”

Where do we see Angles?

Well… Let’s see… Continue with PowerPoint.

Teacher Input

Play Angel songs and show PowerPoint (The Angel of Angles) to introduce today’s lesson on angles.

Pass out student notes.

Define different types of angles: Right, Straight, Acute, Obtuse (Tree Map)

Talk about how you measure and draw angles with a protractor.

Move on to “Pairs of Angles”. Ask students how many a “pair” is. They should say 2.

Discuss these pairs of angles: Complementary, Supplementary, Vertical, and Adjacent Complementary Trick: Starts with a “C”. Draw a “C” on the board. The “C” can be turned into a number.

Supplementary Trick: Starts with a “S”. Draw a “S” on the board. The “S” can be turned into a number.

Explain and demonstrate how to use what you have just learned about angles to find the measurements of missing angles.

Allow students to work the “you try” problems. (Independently)

Classwork: Practice sheets involving angles. (In Groups or Think, Pair, Share)

Assessment Question students for understanding. Monitor students as they work on their classwork.

Closure

What is an acute angle? Less than 90 degrees

What is an obtuse angle? More than 90 degrees but not 180 degrees

How many degrees is a straight line? 180

How many degrees is a right angle? 90

Complementary angles together equal how may degrees? (Think of corner) 90

Supplementary Angles together equal how many degrees? (Think straight line) 180 Vertical angles are _____________? Equal Describe what adjacent angle are. Angles that are next to each other. They share a side.

Student Notes Angles Lesson 8.3.1

Section 1 – Angle Types

Angle Types

Right Angle Straight Angle Acute Angle Obtuse Angle

Measures exactly 90° Measures exactly 180° Measures less than 90° Measures greater than 90°

Draw your own example of the following angles without a protractor:

Acute Angle

Right Angle

Straight Angle

Obtuse Angle

Section 2 – Measuring and Drawing Angles

Protractors have two sets of numbers going in opposite directions.

Be careful which ones you use!

When in doubt, think…

Should this angle be bigger or smaller than 90º ?”

1) Use a protractor to measure the following angles:

a.

This is an acute angle. We know that

acute angles are smaller than 90°.

Which scale should we use to measure

our angle? top -or- bottom

What is the measurement?

Answer: __________

b. This is an obtuse angle. We know that

obtuse angles are bigger than 90°.

Which scale should we use to measure

our angle? top -or- bottom

What is the measurement?

Answer: __________

2) Draw the following angles using a protractor. Identify the type of angle you drew.

a. 75° b. 160° c. 90°

Section 3 – Pairs of Angles

Complementary Angles – Two angles that add together to equal exactly 90°

Tip! Complementary Angles make a Corner.

Supplementary Angles – Two angles that add together to equal exactly 180°

Tip! Supplementary Angles make a Straight Line

Adjacent Angles – Angles that are next to one another.

They share a side.

A and B are adjacent angles.

Vertical Angles – Angles that are across from one another (or opposite).

Vertical angles have equal measurements.

A and B are vertical angles.

D and C are vertical angles.

Angles and Pairs of Angles

Guided Practice

Use facts about supplementary, complementary, vertical and adjacent angles to find

the missing measurements (m).

Example 1. Supplementary angles (180ᵒ) Example 2. Complementary angles (90ᵒ)

m YNB = _________ m BTZ = _________

m TNB = 106 m ZTG = 49

Example 3. Vertical angles

m ZKF = 96º m EKU = _________

m UKF = _________

m EKZ = _________

Example 4 – Measuring Angles.

This is an obtuse angle. We know that obtuse angles are bigger than 90°.

Which scale should we use to measure G? top -or- bottom

What is the measurement of G? Answer: __________

W

Angles and Pairs of Angles

You Try!

Use facts about supplementary, complementary, vertical and adjacent angles to find

the missing measurements (m).

1. 2.

m SEN = _________ m SGU = _________

m ZEN = 148 m UGX = 29

3.

m KTS = 81º

m QTV = _________

m KTQ = _________

m VTS = _________

4.

m W = _________

Name: ________________ Angles and Pairs of Angles

Period: _____

1) Classify each angle as acute, obtuse, right, or straight.

2) Find the measure of the complement of each angle.

3) Find the measure the supplement of each angle.

4) Use what you know about vertical and supplement angles to find each missing angle.

5) Answer the following questions about adjacent angles.

a) Name two angles adjacent to BAF. ________ ________

b) Name two angles adjacent to KAL. ________ ________

c) Name two angles adjacent to JAM. ________ ________

A

B C

A

B C

A

B Z

Name: ___________________ Angles and Angle Pairs

Period: _______

1. 2.

m ∠ABC ______________° m ∠Z ______________°

3. Using what you know about angles to match each measurement to the correct angle.

30º 90º 180º 160º 110º

__________° __________° __________° __________° __________°

4. What angle measure is complementary to 73º? ______________°

5. What angle measure is supplementary to 56º? ______________°

See Back

A B C

F

E

30º

60° 45º

45º

D

Use the diagram below to answer questions 6 – 11.

6. Which angle is obtuse? 7. Which angle is acute?

A. ∠FBC A. ∠DBE

B. ∠DBA B. ∠ABC

C. ∠DBC C. ∠DBF

D. ∠EBC D. ∠CBE

8. Which angle is complementary to ∠EBF ? 9. Which angle is supplementary to ∠ABD ?

A. ∠DBE A. ∠ABC

B. ∠FBC B. ∠FBC

C. ∠DBF C. ∠DBF

D. ∠CBE D. ∠DBC

10. Name a straight angle? ∠____________________

11. Name two right angles? ∠____________________ ∠____________________

12. Name an angle adjacent to ∠FBC ∠ ____________________

Answer Key Angles and Pairs of Angles

1) Classify each angle as acute, obtuse, right, or straight.

2) Find the measure of the complement of each angle.

3) Find the measure the supplement of each angle.

4) Use what you know about vertical and supplement angles to find each missing angle.

A

B C

A

B C

A

B Z

Answer Key Angles and Angle Pairs

1. 2.

m ∠ABC __120°___ m ∠Z ___25° __

3. Using what you know about angles to match each measurement to the correct angle.

30º 90º 180º 160º 110º

____30____° ___160____° ___180____° ___110____° ____90____°

4. What angle measure is complementary to 73º? ___17____°

5. What angle measure is supplementary to 56º? ___124___°

See Back

A B C

F

E

30º

60° 45º

45º

D

Use the diagram below to answer questions 6 – 11.

6. Which angle is obtuse? 7. Which angle is acute?

A. ∠FBC A. ∠DBE

B. ∠DBA B. ∠ABC

C. ∠DBC C. ∠DBF

D. ∠EBC D. ∠CBE

8. Which angle is complementary to ∠EBF ? 9. Which angle is supplementary to ∠ABD ?

A. ∠DBE A. ∠ABC

B. ∠FBC B. ∠FBC

C. ∠DBF C. ∠DBF

D. ∠CBE D. ∠DBC

10. Name a straight angle? ∠ABC (sample answer)

11. Name two right angles? ∠EBC , ∠EBA

12. Name an angle adjacent to ∠FBC ∠EBF