4.5 Angle Relationships and Triangles

Front

What is the sum of the interior angles of a triangle?

Back

The sum of the interior angles of a triangle is always 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

Define complementary angles.

Back

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

Front

Define supplementary angles.

Back

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

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90 degrees.

Front

If two parallel lines are cut by a transversal, what can be said about the alternate interior angles?

Back

The alternate interior angles are equal.

Front

What is the measure of an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is the measure of an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees.

Front

If angle 1 is 50 degrees, what is the measure of its complement?

Back

The complement of angle 1 is 40 degrees (90 - 50 = 40).

Front

If angle 2 is 130 degrees, what is the measure of its supplement?

Back

The supplement of angle 2 is 50 degrees (180 - 130 = 50).