How to cut railed horizontal fence boards for a 50-degree angle

carpentryfencesawwoodworking

I am installing a horizontal WPC wood composite fence that uses aluminum posts with embedded rails. The tongued boards measure 0.6" x 6" x 72". I need to make one 50-degree turn in the fence. The fence manufacturer sent me this diagram:

WPC Fence Angle Cuts

What's the easiest way to cut these angles on the end of 13 boards? I have a 12" compound miter saw and I could probably get access to a table saw, but is there some kind of jig that I could use or make or anything else that might be the easiest way to cut these boards?
WPC Board
Post

Best Answer

screw a fillet piece to the end of the boardscorner fillet

the result will be much stronger than trying to cut the board to fit in the post, and will look better.