Estimating Angles

Front

What is an angle?

Back

An angle is formed by two rays (sides) that meet at a point called the vertex.

Front

What is the vertex of an angle?

Back

The vertex is the point where the two rays of an angle meet.

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 estimate an angle?

Back

To estimate an angle, compare it to known angles like 90º, 180º, and 360º.

Front

What is the best estimate for an angle that looks larger than a right angle but smaller than a straight angle?

Back

The best estimate would be an obtuse angle, which is between 90º and 180º.

Front

What is the best estimate for an angle that looks smaller than a right angle?

Back

The best estimate would be an acute angle, which is less than 90º.

Front

What is the measure of a full rotation?

Back

A full rotation measures 360 degrees.