In this video the author show how to find the volume of a sphere. The formula for finding the volume of a sphere is 4/3 * Pi * r*r*r, where r is the radius of the sphere. Now to compute the volume of a sphere you have to note down the radius of the sphere and substitute it in the above formula along with the other substitutions. The author shows this with an example by taking a sphere of some radius and calculating its volume. To find out how to calculate the volume of a sphere watch this video tutorial.