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Classify an angle of 180

Step by step, with the reason for every step · Classifying angles and triangles · Geometry

Step by step

The question

Question: find what kind of angle 180° 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°.

180 is exactly 180.

180 = 180

Careful!

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

Careful: straight: exactly a straight line

2 Name it

So 180° is straight.

180° is straight

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 the straight line.

So it is a straight angle.

Let's look back.

First: compare with 90° and 180°.

Then: name it.

Last: check.

Answer
180° is straight

Your turn

Try this one yourself, then check:

What kind of angle?
Show the answer
obtuse

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