7th Grade · Geometry

Scale Factor

7.G.A.1

Definition

The ratio of corresponding dimensions of two similar figures. Multiply original dimensions by the scale factor to find the new dimensions.

Examples

  • New 12cm ÷ original 4cm = scale factor 3 (enlargement).
  • Scale factor 1/2 means the new figure is half the original size — a reduction.

Key rule

Scale factor greater than 1 is enlargement; less than 1 is reduction.

Memory hook

Multiply by the scale factor to resize.