get a point out of circle.arc

[Felix Fischer]

hi everybody,

i want to have rectangles emerging on different positions on the screen. 
their positions should depend on distance from a specific point and 
angle to x-axis.

i can easily reach the points by drawing an arc:

cnvs.Arc XRes/2, YRes/2, c.getattrib("distance"), 0, c.getattrib("angle")

is there a possibility to get the coordinates of the arc's last point? 
later, this should be the middle of the rectangle. or, do you suggest an 
easier way to draw those rectangles, using "distance" and "angle"?

thank you for your help
felix fischer