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

How many degrees are in a full circle?

Back

There are 360 degrees in a full circle.

Front

What is 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 more than 90 degrees but less than 180 degrees.

Front

What is a straight angle?

Back

A straight angle measures exactly 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 read the measurement where the other ray crosses the numbered scale.

Front

What is the measurement of a 90-degree angle?

Back

A 90-degree angle is a right angle.

Front

What is the measurement of a 180-degree angle?

Back

A 180-degree angle is a straight angle.