Geometry · Quadrilaterals & Polygons

Rectangle

HSG-CO.C.11

Definition

A parallelogram with four right angles and congruent diagonals.

Examples

  • A rectangle's diagonals are always equal in length.
  • Every rectangle is a parallelogram, but not every parallelogram is a rectangle.

Key rule

A rectangle is a parallelogram with four 90 degree angles.

Memory hook

A parallelogram with all right angles.