Classifying 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

A right angle measures exactly 90 degrees.

Front

What is an acute angle?

Back

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

Front

What is an obtuse angle?

Back

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

Front

What is a straight angle?

Back

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

Front

If m∠A = (5x + 25)° and x = 7, find m∠A.

Back

m∠A = (5(7) + 25)° = 60°.

Front

What is the angle formed by two intersecting lines called?

Back

The angle formed by two intersecting lines is called a vertical angle.

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

How do you name an angle formed by two lines?

Back

An angle can be named using three points, with the vertex point in the middle, such as ∠FED.