7th Grade · Geometry

Cross-Section

7.G.A.3

Definition

The two-dimensional shape formed when a flat plane intersects a three-dimensional solid. The shape depends on the solid and the angle of the cut.

Teach it

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

Examples

  • A rectangular prism sliced parallel to its base gives a rectangle.
  • A cone or sphere sliced through the center gives a circle.

Key rule

Slicing at an angle can produce a different shape than slicing straight across.

Memory hook

Slice the solid — what shape do you see?