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 measurements?

Back

Acute (less than 90°), Right (exactly 90°), Obtuse (more than 90° but less than 180°).

Front

What is an acute angle?

Back

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

Front

What is a right angle?

Back

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

Front

What is an obtuse angle?

Back

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

Front

What is a straight angle?

Back

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

Front

How do you name an angle formed by three points?

Back

You name the angle using the vertex point in the middle, for example, ∠KLM.

Front

What type of angle is 25°?

Back

25° is an acute angle.

Front

What type of angle is 90°?

Back

90° is a right angle.