Sum and Inequality Theorem

Find the measure of the missing angle.

• 30^o
• 110^o
• 150^o
• 40^o

Will the following three angles for a triangle?

30°, 60°, 90°

• yes

• no

A student is trying to construct triangles using four different sets of angles. The angles in each set are given below. Which set will form a triangle?

• 45°, 65°, 70°

• 150°, 110°, 100°

• 50°, 50°, 50°

• 90°, 90°, 90°

Which sets of measurements could be the interior angles of a triangle? Select EACH correct answer.

• 15°, 15°, 150°

• 10°, 90°, 100°

• 30°, 30°, 115°

• 10°, 80°, 90°

• 60°, 60°, 60°

A triangle has one angle that measure 81° and one that measures 37°. What is the measure of the third angle?

• 62°

• 76°

• 118°

• 99°

A triangle has one angle that measure 45° and one that measures 60°. What is the measure of the third angle?

• 135°

• 75°

• 120°

• 105°

Will these three sides form a triangle?

• yes

• no

Will these side lengths form a triangle?

• yes

• no

Does a triangle with these side lengths exist?

15, 12, 9

• Yes

• No

• I don't know.

• Cannot be determined

Can the sides of a triangle have lengths 3, 4, and 9?

• Yes

• No

• I don't know

• Cannot be determined