Rotations are simply "spins" or "turns" around a point; sometimes that point is the origin, sometimes it is not. [br][br]Rotations are considered rigid transformations because they preserve the same shape and size of the original object.[br][br]Clockwise --> This is a rotation in the same direction as the numbers on a clock.
A rotation of [math]90^o[/math] clockwise about the origin will map (x, y) -->
A rotation of [math]180^o[/math] clockwise about the origin will map (x, y) -->
A rotation of [math]180^o[/math] clockwise is the same as a reflection over y = x.