Finding the Missing Angle

Front

What is the sum of the angles in a triangle?

Back

The sum of the angles in a triangle is always 180°.

Front

What are complementary angles?

Back

Complementary angles are two angles whose measures add up to 90°.

Front

What are supplementary angles?

Back

Supplementary angles are two angles whose measures add up to 180°.

Front

If m∠1 = 30°, what is m∠3 if they are equal?

Back

m∠3 = 30°.

Front

Which of the following sets of angles can form a triangle: 120°, 50°, 20°?

Back

No, because 120° + 50° + 20° = 190°, which is greater than 180°.

Front

If ∠H and ∠J are complementary and ∠H = 35°, what is ∠J?

Back

∠J = 90° - 35° = 55°.

Front

What is the value of x if x + 72° = 180°?

Back

x = 180° - 72° = 108°.

Front

What is the measure of an angle that is supplementary to 37°?

Back

The angle is 180° - 37° = 143°.

Front

If two angles are supplementary and one angle measures 118°, what is the other angle?

Back

The other angle is 180° - 118° = 62°.

Front

What is the measure of the third angle in a triangle if the other two angles are 40° and 50°?

Back

The third angle is 180° - (40° + 50°) = 90°.