How to work out a circle's radius: Easy way of working it out
What is a circle's radius?
A circle's radius is the measurement from the center point of a circle to the outer perimeter. For the easiest way to work out a circle's radius you will need to know what the circle's diameter is.
Working out the radius from the diameter
The formula is as follows:
D/2
Very simple. If you need a further explanation however, all this means is that you divide the diameter by 2 - or in other words, half the length of the diameter.