A 90° Rotation About the Origin

A rotation is described by the angle the shape turns about a center of rotation.

The shape above has been rotated 90° clockwise (the angle of reflection) about the origin (0, 0) (the center of rotation).

Real Examples of a Rotation of 90° About the Origin

All of the following shapes have been rotated by 90° clockwise about the origin:

How to Describe 180°, 270° and 360° Rotations About the Origin

180°, 270° and 360° rotations about the origin are also commonly examined:

Geometry Lessons
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Top Tip
90° IS A QUARTER TURN

90° is a quarter turn.

Note
WHAT IS A ROTATION?

A rotation turns a shape around a center.

A rotation is a type of transformation.

HOW TO THINK OF ROTATIONS OF 90° ABOUT THE ORIGIN

Imagine a shape is drawn on a pair of axes on a sheet of paper...

Imagine sticking a pin through the origin and into a surface.

If you span the paper around, the pin would stay in place and every other point on the paper would turn in a circle around it.

By turning the paper a quarter turn, a 90° rotation about the origin will take place.