Pairs of Angles

Front

What are complementary angles?

Back

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

Front

What are vertical angles?

Back

Vertical angles are the angles opposite each other when two lines intersect. They are always equal.

Front

If two angles are supplementary, what is the sum of their measures?

Back

The sum of the measures of supplementary angles is 180 degrees.

Front

What is the measure of an angle that is complementary to a 45° angle?

Back

The measure of the angle is 45° (90° - 45° = 45°).

Front

How can you name an angle using three points?

Back

An angle can be named using three points: the vertex point in the middle and one point from each ray.

Front

What is the value of the unknown angle if one angle is 83° and they are supplementary?

Back

The unknown angle is 97° (180° - 83° = 97°).

Front

What is an example of a pair of complementary angles?

Back

81° and 9° are complementary angles because 81° + 9° = 90°.

Front

Which angle is NOT a way to name the angle?

Back

∠BCA is NOT a valid way to name the angle if the points do not form a valid angle.

Front

If ∠2 measures 83°, what is the measure of ∠3 if they are vertical angles?

Back

∠3 also measures 83° because vertical angles are equal.

Front

What is the measure of an angle that is supplementary to a 97° angle?

Back

The measure of the angle is 83° (180° - 97° = 83°).