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One angle of a regular hexagon

Step by step, with the reason for every step · Angles in a polygon · Geometry

Step by step

The question

Question: find one interior angle of a regular hexagon.

1 Cut into triangles

A hexagon has 6 sides and 6 corners.

A polygon is a flat shape with straight sides.

Interior angles are the angles inside, at the corners.

Regular means all the sides are equal, and all the angles are equal.

Pick one corner.

Draw lines from it to the other corners.

They cut the hexagon into triangles.

Count them: 1, 2, 3, 4.

Each triangle sits on one side of the hexagon, away from our corner.

The two sides that touch our corner have no triangle of their own.

So there are 2 fewer triangles than sides: 6 − 2 = 4.

triangles = 6 − 2 = 4

2 Add the triangles

The angles in each triangle add up to 180°.

Together, the triangles make all the angles of the hexagon.

4 triangles, 180° each: 4 times 180 is 720.

sum = 4 × 180 = 720

3 Share it out

All 6 angles are the same.

So we share 720° equally: 720/6.

one angle = 7206

720 divided by 6 is 120.

So each angle is 120°.

one angle = 120°

4 Check

Let's check: 6 angles of 120° together.

6 × 120 = 720

We get 720°, the angle sum.

So 120° is right!

Let's look back.

First: cut into triangles.

Then: add the triangles.

Then: share it out.

Last: check.

Answer
one angle = 120°

Your turn

Try this one yourself, then check:

Find one angle of a regular dodecagon.
Show the answer
one angle = 150°

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