Rotation

In mathematics, when we are talking about rotations, we are talking about movements around a centre point along the path of a circle. The rotation can be in a clockwise or anticlockwise direction.

In the diagram below, point P is rotated in a clockwise direction around the origin (0, 0).

In order to know the size of the rotation, we can draw a line segment from the centre of rotation, (0, 0), to P and a line segment from (0, 0) to P′. Then we can measure the angle between these two line segments.

The angle is 90°. The rotation from P to P′ is 90° in a clockwise direction about the origin.