Basic Angle Relationships

Front

What is a vertical angle?

Back

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

Front

What are supplementary angles?

Back

Supplementary angles are two angles that add up to 180°.

Front

What are complementary angles?

Back

Complementary angles are two angles that add up to 90°.

Front

What is the relationship between angle 1 and angle 5 if they are opposite each other when two lines intersect?

Back

Angle 1 and angle 5 are vertical angles.

Front

What is the relationship between angle 2 and angle 4 if they add up to 180°?

Back

Angle 2 and angle 4 are supplementary angles.

Front

What is the relationship between angle 3 and angle 6 if they add up to 90°?

Back

Angle 3 and angle 6 are complementary angles.

Front

If two angles are adjacent and form a straight line, what is their relationship?

Back

They are supplementary angles.

Front

If angle A is 30° and angle B is its complement, what is the measure of angle B?

Back

Angle B is 60° because 30° + 60° = 90°.

Front

If angle C is 120° and angle D is its supplement, what is the measure of angle D?

Back

Angle D is 60° because 120° + 60° = 180°.

Front

What is the sum of the measures of two complementary angles?

Back

The sum is 90°.