Geometry · Area, Surface Area & Volume

Cross-Section

HSG-GMD.B.4

Definition

The two-dimensional shape formed when a plane cuts through a three-dimensional figure.

Examples

  • A horizontal slice through a cylinder produces a circle as its cross-section.
  • A vertical slice through a rectangular prism produces a rectangle.

Key rule

The shape of a cross-section depends on the angle and direction of the slice.

Memory hook

The flat shape revealed by a slice.