Go here:
Polygon Angle Program Do you find that those tables of saw angles for compound miter setups never seem to have the numbers you want -- like for that 7-sided polygon with steeply sloping sides? Do sine and cosines give you a headache that reminds you of why you hated trigonometry class in high school? If so, this Windows95/98 program might be for you. It calculates the proper angles for polygons having 3 to 16 sides and side slopes from 0 to 60 degrees. It also shows you graphically what you need to cut and will even print out a drawing for you to take to the shop. Self-installing executable, 800k
Dan.