3-D Shape Formulas

Geometric Figure Surface Area Volume
Cylinder

Sphere
Cone

Square-based Pyramid

Rectangular Prism
Triangular Prism

Deriving Formulas with Calculus

Fact

Surface area is the derivative of volume, and by Fundamental Theorem of Calculus#Fundamental Theorem of Calculus, Part 2 (FTC 2), volume is the integral of surface area.

Example - Sphere

With the volume , taking the derivative: .

Conversely, with the surface area formula, setting our bounds from , we have .

Intuition

You can think of the volume of the sphere as the surface area of many spheres of increasing radius added together. That is, the volume of any shape is really the Riemann Sum of some surface area.

Example - Cylinder

The surface area of a cylinder has multiple components to it. We should notice that the surface areas are just the Partial Derivatives of the separate variables:
With , we have , and .

Conversely, integrating either of these formulas will give us the volume again:
Integrating the from 0 to gives .
Integrating the from 0 to gives