Angle of cut
 

I need the angle I should be mitering for a decagon shape, 10 sided shape.

Angle of cut
 

What should the mitre saw angle be for a decagon (10 sided) frame be?

Depends. Are all sides equal? And are you just trying to miter, or compound miter? Are you trying to make some kind of flat picture frame or?

Actual angle--36 * miter angle 18*

angle of mitre saw for decagon frame
 

All sides are the same. I'm making a decagon (10 sided) waterbed frame, and the side boards are 1"x 9"x 29". The boards will be on edge, so I need the angle to set my mitre saw at. Thanks.

360 degrees in a circle--divide by the number of corners--then half of that for the miter angle--

For shapes in a simple plane ...

180 degrees divided by the number of sides

examples

180 / 4 sides = 45 degrees
180 / 6 sides = 30 degrees
180 / 10 sides = 18 degrees

Google is your friend....

http://en.wikipedia.org/wiki/Decagon

The angle depends on which reference you want. Internal angle is 144 deg.....or 36 deg from each point....(360 deg/10)