Angles on a Protractor - 4th Grade

Front

What is an angle?

Back

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

Front

What is a protractor used for?

Back

A protractor is a tool used to measure angles in degrees.

Front

What is the measurement of a right angle?

Back

A right angle measures 90 degrees.

Front

What is the measurement of a straight angle?

Back

A straight angle measures 180 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 more than 90 degrees but less than 180 degrees.

Front

How do you read a protractor?

Back

To read a protractor, align the baseline of the protractor with one ray of the angle and find the measurement where the other ray intersects the numbered scale.

Front

What is the measurement of a full rotation?

Back

A full rotation measures 360 degrees.

Front

If an angle measures 75 degrees, is it acute, right, or obtuse?

Back

It is an acute angle.

Front

If an angle measures 130 degrees, is it acute, right, or obtuse?

Back

It is an obtuse angle.