Find Angle Measures

Finding Unknown Angle Measurements

What do we already know?

Angle ABC = 40 $\degree$  

What else do we know?

Solve for  $\angle$  CBH
90 $\degree$  - 40 $\degree$  = ?

Where did 90 $\degree$ come from? 

90 $\degree$  is the measure of  $\angle$  ABH which is a right angle.

Complementary Angles

are two angles that add up to 90°

Example from the picture to the right: 40° + 50° = 90°

More

Examples: 45° + 45° = 90°

Example: 82° + 8° = 90°

Multiple Choice

Find the measure of $$\angle$$  DEG

• 46 $$\degree$$  

• 36 $$\degree$$  

• 90 $$\degree$$  

• 126 $$\degree$$  

Fill in the Blanks

The measure of $\angle$  UST is

degrees.

Fill in the Blanks

The measure of $\angle$  CEG is

degrees.

Multiple Choice

Which pair of angle measurements are complementary?

• 18 $$\degree$$ 72 $$\degree$$

• 50 $$\degree$$ 30 $$\degree$$

• 25 $$\degree$$ 75 $$\degree$$

• 45 $$\degree$$ 35 $$\degree$$

Multiple Choice

What is the measurement of angle a?

• 30 $$\degree$$

• 25 $$\degree$$

• 90 $$\degree$$

• 60 $$\degree$$

Supplementary Angles

Two angles that add up to 180°

Examples: 120° + 60°= 180°

Example: 84° + 96°= 180°

What is the measure of angle a if angle b measures 68 $\degree$  ?

Notice that a and b together equal a straight line.

Multiple Choice

 Find the measure of $$\angle$$  PQS

• 34 $$\degree$$  

• 56 $$\degree$$  

• 146 $$\degree$$  

• 180 $$\degree$$  

Multiple Choice

Angle MNP and Angle PNO have a combined measure of 180 $$\degree$$
The measure of  $$\angle$$  MNP is 87 $$\degree$$  

What is the measure of  $$\angle$$  PNO in degrees?
The measure of  $$\angle$$  PNO is ____________ degrees.

• 87 $$\degree$$  

• 3 $$\degree$$  

• 93 $$\degree$$  

• 103 $$\degree$$  

Multiple Choice

Angle ABC is divided into 2 smaller angles by a ray. One of the smaller angles formed is an obtuse angle and the other is an acute angle. Which of the following could NOT be the measure of angle ABC?

• 79 $$\degree$$

• 93 $$\degree$$

• 107 $$\degree$$

• 119 $$\degree$$

Angles on a Straight Line Add Up to 180

What does angle b equal?

Fill in the Blanks

The measure of angle XYZ equals

degrees.

Fill in the Blanks

The measurement of WYV is

degrees.

Fill in the Blanks

What is the measure of angle FGJ 

if angle JGH measures 22 $\degree$  ?

Its measurement is

degrees.

Fill in the Blanks

What is the meaure of angle EGF if angle FGH is a right angle?

The measurement of angle EGF is

degrees.

Multiple Choice

What is the measure of angle KGH 

if angle EGK measures 59 $$\degree$$ ?

The measurement of angle KGH is ______ degrees.

• 59 $$\degree$$  

• 31 $$\degree$$  

• 180 $$\degree$$  

• 121 $$\degree$$  

Multiple Choice

Angle AED and angle DEC are adjacent right angles. Together, they form angle AEC. What type of angle is angle AEC?

• acute

• obtuse

• right

• straight

Fill in the Blanks

Two adjacent angles form a 76 $\degree$  angle.

The smaller angle measures 28 $\degree$ . 

What is the measure of the larger angle?