8th Grade · Geometry

Volume

8.G.C.9

Definition

The amount of three-dimensional space a solid occupies, measured in cubic units. Cylinders, cones, and spheres each have their own volume formula involving pi.

Teach it

Where it is taught, with guided notes, practice, homework, an exit ticket and an interactive Teacher Deck.

Examples

  • Cylinder: V = πr2h.
  • Cone: V = (1/3)πr2h. Sphere: V = (4/3)πr3.

Key rule

Cylinder, cone, and sphere all use pi and the radius, but the cone has 1/3 and the sphere uses r cubed.

Memory hook

Space inside a solid, measured in cubic units.