Triangle Sum and Exterior Angle Theorem Lesson

​Objective: Is to apply the Triangle Sum Theorem and understand to solve the missing angle

-Works if you know two angles in a triangle...

-All sums of the angles of a triangle equals 180​

​Some text here about the topic of discussion.

​Triangle Sum THeorem

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Multiple Choice

The Triangle Sum Theorem states that the sum of all angles in a triangle is ______. 

• 45°
• 90°
• 180°
• 360°

Multiple Choice

If two angles in a triangle are $$45\degree$$  and $$\ 75\degree$$ , what is the measure of the third angle?

• $$75\degree$$  

• $$90\degree$$  

• $$60\degree$$  

• $$70\degree$$  

Multiple Choice

Find the measure of the indicated angle.

• $$135\degree$$  

• $$55\degree$$  

• $$45\degree$$  

• $$60\degree$$  

Multiple Choice

Find the measure of the indicated angle.

• $$30\degree$$  

• $$25\degree$$  

• $$155\degree$$  

• $$65\degree$$  

Multiple Choice

Find the measure of the indicated angle.

• $$45\degree$$  

• $$33\degree$$  

• $$123\degree$$  

• $$147\degree$$  

​Exterior angle Theorem

• Angle 50, 70, and x are interior angles

• Angles inside the triangle not adjacent

• are remote interior angles

• 50+70=120 add your remote interior angles to equal the exterior angle

• The exterior angle is 120

• x=60 and is linear pair to 120. 120+60=180​

Multiple Choice

What is the value of the missing angle?

• 90

• 100

• 20

• 120

Multiple Choice

What is the value of the missing angle?

• 105

• 80

• 55

• 25

Multiple Choice

What is the value of the missing angle?

• 90

• 100

• 20

• 120

Multiple Choice

Find the measure of the missing angles.

• A

• B

• C

• D

Multiple Choice

What is the value of the missing angle?

• 105

• 80

• 55

• 25