The surface area of a sphere is given by

$.$ Declare double variables sphereRadius and sphereArea. Then, read sphereRadius from input and compute sphereArea using the formula.

Ex: If the input is $3\mathrm{.}90,$ then the output is:

$191\mathrm{.}13$

Note:

Use the constant Math.PI for

$.$

can be computed using $*.$