Classify an angle of 89

Step by step

The question

Question: find what kind of angle 89° is.

1 Compare with 90° and 180°

There are five kinds of angles.

Each name says how big the angle is, next to 90° and 180°.

89 is less than 90.

Careful!

Look at the size next to 90° and 180°.

2 Name it

So 89° is acute.

3 Check

Let's check with the picture.

The dashed line up makes a square corner: 90°.

The dashed line to the left makes a straight line: 180°.

Our angle is smaller than the square corner.

So it is acute.

Let's look back.

First: compare with 90° and 180°.

Then: name it.

Last: check.