angles grade 4

Front

What is an angle?

Back

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

Front

What are the types of angles?

Back

The main types of angles are acute (less than 90°), right (exactly 90°), obtuse (more than 90° but less than 180°), and straight (exactly 180°).

Front

What is an acute angle?

Back

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

Front

What is a right angle?

Back

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

Front

What is an obtuse angle?

Back

An obtuse angle is an angle that measures more 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

How do you measure an angle using a protractor?

Back

To measure an angle with a protractor, align the protractor's baseline with one ray of the angle, and read the measurement where the other ray crosses the protractor.

Front

What is the measure of a right angle?

Back

The measure of a right angle is 90 degrees.

Front

What is the measure of an acute angle?

Back

An acute angle measures less than 90 degrees.

Front

What is the measure of an obtuse angle?

Back

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