Angles

Front

What is an angle?

Back

An angle is formed by two rays (sides of the angle) that share a common endpoint (the vertex).

Front

What are complementary angles?

Back

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

Front

What are supplementary angles?

Back

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

Front

What are vertical angles?

Back

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

Front

What are corresponding angles?

Back

Corresponding angles are angles that are in the same position at each intersection where a straight line crosses two others. They are equal when the lines are parallel.

Front

What are alternate interior angles?

Back

Alternate interior angles are pairs of angles on opposite sides of a transversal but inside the two lines. They are equal when the lines are parallel.

Front

What are alternate exterior angles?

Back

Alternate exterior angles are pairs of angles on opposite sides of a transversal but outside the two lines. They are equal when the lines are parallel.

Front

How do you find the measure of an unknown angle in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees. To find an unknown angle, subtract the sum of the known angles from 180 degrees.

Front

What is the relationship between angles 1 and 2 if they are supplementary?

Back

If angles 1 and 2 are supplementary, their measures add up to 180 degrees.

Front

What is the measure of a right angle?

Back

A right angle measures 90 degrees.