8th Grade · Geometry
Rotation
8.G.A.3
Definition
A transformation that turns a figure about a fixed center point by a specified angle and direction. The image is congruent to the original.
Examples
- 90° CCW about the origin: (x,y) → (-y,x).
- Size and shape stay the same — only the orientation changes.
Key rule
A rotation is a rigid motion — the image stays congruent to the original.
Memory hook
A turn around a fixed center point.