Area and Perimeter of a Circle - Geometry Calculator

An online calculator to calculate the area \( A \) and perimeter \( P \) of a circle given its radius \( r \) given by: \[ P = 2 \pi r \] \[ A = \pi r^2 \]

How to use the calculator

Enter the radius \( r \) as a positive real number and press "calculate". The outputs are the area and perimeter of the circle.