Congruent Triangles Triangle Angle Sum

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

• 45°

• 90°

• 180°

• 360°

Find the indicated angle measure. (What is ?)

• 51°

• 37°

• 167°

• 41°

Tell whether the triangles are similar. Explain.

• Yes because why not

• No because x = 107

• Yes because the triangles have at least two congruent angles.

• Nah

Find the value of x if the two triangles are similar.

• x = 45

• x = 3

• x = 12

• x = 90

Which triangles are similar to triangle A?

• B

• C

• Both

• None

What are the ways that we can use to prove two triangles are congruent? (Mark all that apply)

• SSS

• SAS

• ASA

• AAS

• SSA

The sum of the angle measures of a triangle is 180° 
m∠A + m∠B + m∠C = 180°

• Triangle Sum Theorem

• Exterior Angle Theorem

• Third Angle Theorem

• Centroid Theorem

If two angles of one triangle are congruent to two angles of another triangle, then the third pair of angles are congruent.

• Triangle Sum Theorem

• Exterior Angle Theorem

• Third Angles Theorem

• Congruent Triangles Theorem

What is the correct congruence statement?  ΔDEC ≅________

• ΔAEB

• ΔEAB

• ΔBEA

• Not Congruent

Solve for x

• 30°

• 40°

• 50°

• 60°