How to Solve for Radius in Excel. The radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference.

Find the diameter and the radius of a circle with a circumference of 465 cm. Give the answer to the nearest centimetre. Use π = 3۰142 or the π button on a calculator.

Going further, if you used 40 digits of pi, Rayman says, you could calculate the circumference of the entire visible universe — an area with the radius of about 46 billion light-years — “to ...