Pentagon Rotation Puzzle

pentagon' is pentagon rotated around point O.[br][br]a. Use the slider and change the angle of rotation until pentagon' and pentagon are in the same position.[br]b. What angles of rotation result in pentagon' being in the exact same location as pentagon?[br][br]Hint: you can use the -1 and the +1 buttons to more precisely control the angles.

Information: Pentagon Rotation Puzzle