A rotation is a type of geometrical transformation in which the vertices of a shape are rotated at a certain angle around a fixed point (called the center of rotation).^[1] In simpler terms, imagine gluing a triangle to the second hand of a clock that is spinning backwards. Usually, you will be asked to rotate a shape around the origin, which is the point (0, 0) on a coordinate plane. You can rotate shapes 90, 180, or 270 degrees around the origin using three basic formulas.