能在一个平面坐标系中画一个五角星，输入指定的坐标点P(x,y)以及这个五角星绕P点旋转的角度a,运行就可以让五角星绕P点旋转的角度a。-In a plane coordinate system in a draw five-pointed star, enter the designated point coordinates P (x, y), as well as the five-pointed star around the P point of rotation angle a, ca