Rotates the amount specified by the angle parameter. Angles must be specified in radians (values from 0 to TWO_PI), or they can be converted from degrees to radians with the radians() function.
The coordinates are always rotated around their relative position to the origin. Positive numbers rotate objects in a clockwise direction and negative numbers rotate in the couterclockwise direction. Transformations apply to everything that happens afterward, and subsequent calls to the function compound the effect. For example, calling rotate(PI/2.0) once and then calling rotate(PI/2.0) a second time is the same as a single rotate(PI). All tranformations are reset when draw() begins again.
Technically, rotate() multiplies the current transformation matrix by a rotation matrix. This function can be further controlled by pushMatrix() and popMatrix().
translate(width/2, height/2); rotate(PI/3.0); rect(-26, -26, 52, 52);