Angle Proofs

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 is a right angle?

Back

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

Front

What is a straight angle?

Back

A straight angle is an angle that measures exactly 180 degrees.

Front

What is the Angle Addition Postulate?

Back

The Angle Addition Postulate states that if point B is in the interior of angle AOC, then the measure of angle AOB plus the measure of angle BOC equals the measure of angle AOC.

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 is a linear pair?

Back

A linear pair is a pair of adjacent angles formed when two lines intersect. The angles in a linear pair are supplementary.

Front

What is the definition of an acute angle?

Back

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

Front

What is the definition of an obtuse angle?

Back

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