Classifying Angles

Front

What is an angle?

Back

An angle is formed by two rays (sides) that share a common endpoint (vertex).

Front

What is the vertex of an angle?

Back

The vertex is the point where the two rays of an angle meet.

Front

What are the three types of angles based on their measures?

Back

1. Acute angle: less than 90° 2. Right angle: exactly 90° 3. Obtuse angle: more than 90° but less than 180°.

Front

What is a straight angle?

Back

A straight angle measures exactly 180°.

Front

What is an acute angle?

Back

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

Front

What is an obtuse angle?

Back

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

Front

How do you estimate an angle?

Back

To estimate an angle, compare it to known angles (like 0°, 90°, and 180°) to find a close measure.

Front

What is the measure of a right angle?

Back

A right angle measures exactly 90°.

Front

If an angle measures 76°, what type of angle is it?

Back

It is an acute angle.

Front

If an angle measures 180°, what type of angle is it?

Back

It is a straight angle.