Interior Angle Sum Theorem

Solve for x.

Hint: remember all three angles add up to 180°.

• 70°

• 140°

• 180°

• 30°

The sum of all the interior angles of a triangle is ___ degrees.

What is the measure of ∠ D ?

• 90°

• 66°

• 49°

• 131°

What is the measure of the exterior angle, x °

What is the measure of ∠ M ?

• 146°

• 34°

• 223°

• 69°

Find m∠B.

• 10

• 20

• 30

• 40

Find m∠B and m∠C.

• m∠B = 21°, m∠C = 81°

• m∠B = 7°, m∠C = 21°

• m∠B = 21°, m∠C = 7°

• m∠B = 81°, m∠C = 21°

Find m∠CAB and m∠ABC.

• m∠CAB = 24°, m∠ABC = 26°

• m∠CAB = 25°, m∠ABC = 25°

• m∠CAB = 50°, m∠ABC = 50°

• m∠CAB = 26°, m∠ABC = 24°

Find m∠CAB and m∠ABC.

• m∠CAB = 25°, m∠ABC = 65°

• m∠CAB = 65°, m∠ABC = 25°

• m∠CAB = 10°, m∠ABC = 80°

• It cannot be determined.

Find m∠CAB and m∠ABC.

• m∠CAB = 125°, m∠ABC = 10°

• m∠CAB = 10°, m∠ABC = 125°

• m∠CAB = 45°, m∠ABC = 125°

• m∠CAB = 125°, m∠ABC = 45°