Measuring Angles with a Protractor

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?

Back

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

Tags

CCSS.4.MD.C.6

Front

What is the measurement of a right angle?

Back

A right angle measures 90 degrees.

Tags

CCSS.4.G.A.1

Front

What is an acute angle?

Back

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

Tags

CCSS.4.G.A.1

Front

What is an obtuse angle?

Back

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

Tags

CCSS.4.G.A.1

Front

What is a straight angle?

Back

A straight angle measures exactly 180 degrees.

Tags

CCSS.4.G.A.1

Front

How do you use a protractor to measure an angle?

Back

Align the midpoint of the protractor with the vertex of the angle, then read the measurement where one ray crosses the protractor.

Tags

CCSS.4.MD.C.6

Front

What is the sum of angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Tags

CCSS.8.G.A.5

Front

What is a reflex angle?

Back

A reflex angle is an angle that measures more than 180 degrees but less than 360 degrees.

Tags

CCSS.4.G.A.1

Front

What is the difference between acute and obtuse angles?

Back

Acute angles are less than 90 degrees, while obtuse angles are more than 90 degrees but less than 180 degrees.

Tags

CCSS.4.G.A.1