## Simple instructions for finding the radius of a circle if the diameter is known.

Find the radius of a circle using these simple instructions.

## Instructions

The **radius** of a circle is the distance from the center point to any point on the circle’s perimeter. You use the term * radii* when referring to more than one radius. If you decided to draw two radii at opposite sides, then you would have made a line traverse the entire circle like the example illustrates.

## Formula

If you know the diameter of the circle then you simply divide the diameter by 2 in order to get the radius.

**All posts in this series:** What is a circle? | What is the radius of a circle? | What is the diameter of a circle? | What is the circumference of a circle? | What is the area of a rectangle? | What is the perimeter of a triangle? | What is the area of a triangle?