The area of a circle with radius R is given by S=NR^2. This formula can be directly used, if you know the radius.
The volume of cone has the formula V=1/3*S*h, where S is the area of the base of the cone (the area of a circle, which is "worth" the cone), h is the height of the cone. If the task is known, the volume V of a cone with height h and a square base of the cone is easy to find as S=3V/h.
In the cone it is useful to remember the formula for the area of the conical surface S'=πRL, where L is the generator of the cone (a line connecting the apex of the cone with any point lying on the circumference of the base of the cone). There can be any correlation between the axis of the cone and the base radius, the generatrix of the cone and the radius of the generatrix of the cone and the axis. You must use these data in the solution of the problem, using the fact that the axis of the cone perpendicular to the base of the cone.