Measuring Angles using a Protractor

Front

What is a protractor?

Back

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

Front

How do you read a protractor?

Back

To read a protractor, align the baseline of the protractor with one side of the angle and look at the number where the other side of the angle crosses the scale.

Front

What is the measure of a right angle?

Back

A right angle measures 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.

Front

What is a straight angle?

Back

A straight angle measures exactly 180 degrees.

Front

What is a full rotation in degrees?

Back

A full rotation is 360 degrees.

Front

How do you find the measure of an angle using a protractor?

Back

Place the protractor's center point at the vertex of the angle, align one side with the baseline, and read the measurement where the other side crosses the scale.

Front

What is the measure of a 45-degree angle?

Back

A 45-degree angle is an acute angle that is half of a right angle.

Front

What is the measure of a 180-degree angle?

Back

A 180-degree angle is a straight angle.