Determining 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 is the sum of angles in a triangle?

Back

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

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 pairs of angles that are in similar positions 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 that lie between two lines and on opposite sides of a transversal. They are equal when the lines are parallel.

Front

What are alternate exterior angles?

Back

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

Front

If one angle measures 50 degrees, what is the measure of its complementary angle?

Back

The complementary angle measures 40 degrees (90 - 50 = 40).

Front

If two angles are supplementary and one measures 130 degrees, what is the measure of the other angle?

Back

The other angle measures 50 degrees (180 - 130 = 50).