Surface Areas and Volumes of Spheres If you know the surface area of a sphere, you can find its volume. First, use the surface area formula, S.A. = 4r², to determine the radius of the sphere. Next, substitute the value of its radius into the formula for the volume of a sphere, V = ³. Type your answer and then click or tap Done. The surface area of a sphere is 144 Express your answer in terms of . cm³ Text to Spe cm². What is the volume of the sphere?