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## Ignore words

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Circle

in a plane, the set of all points equidistant from a given point

Center

Each regular polygon has a center because it can be inscribed in a circle.

radius

From center to a point on the circle.

diameter

A straight line passing through the centre of a circle to touch both sides of the circumference.

pi

the ratio of the circumference to the diameter of a circle

Circumference

The distance around a circle