Measure and Classify 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 measure of a right angle?

Back

90 degrees.

Front

What is an acute angle?

Back

An angle that measures less than 90 degrees.

Front

What is an obtuse angle?

Back

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

Front

What is a straight angle?

Back

An angle that measures exactly 180 degrees.

Front

What is a reflex angle?

Back

An angle that measures more than 180 degrees but less than 360 degrees.

Front

What is a vertex in relation to angles?

Back

A vertex is the point where two or more lines meet, forming an angle.

Front

What are complementary angles?

Back

Two angles that add up to 90 degrees.

Front

What are supplementary angles?

Back

Two angles that add up to 180 degrees.

Front

What is the sum of angles in a triangle?

Back

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