# What is the radius of a circle?

A

**radius**is a straight line from the center of a

**circle**to the circumference of a

**circle**. If you have two or more of them, they are referred to as

**radii**. All

**radii**in a

**circle**will be the same length.

Given the diameter of a circle, the radius is simply half the diameter:

radius r = Diameter/2 = D/2

Regards

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