The formula for the area of any regular polygon is 1/2 the product of the apothem and the perimeter. The area of a circle is

with the r standing for "radius".
The formula for the volume of any prism or cylinder is the area of the base times the height of the prism or cylinder. The volume for a sphere is 4/3 the product of

with the r standing for radius.
There are countless other formulas for volume and area, so if the one you are looking for is not here please comment the formula you're looking for and I'll happily supply you with it!