8th Grade · Geometry
Dilation
8.G.A.4
Definition
A transformation that resizes a figure by a scale factor from a center point. The image is similar to the original, with the same shape but a different size.
Examples
- From the origin with scale factor 2: (x,y) → (2x, 2y).
- Scale factor greater than 1 enlarges; between 0 and 1 shrinks.
Key rule
Dilation is NOT rigid — the size changes, but the shape stays similar.
Memory hook
Resize from a center point.