How can I make trapezoid-shaped wood board (beveled edges)?
Sorry. My first answer mis-understoood the question. Based on the updated question, there are many ways to create a shape of the desired profile, based on what tools you have or can find/buy/etc.


Rip the edges with an angled tablesaw blade.
A handheld power (circular) saw, with the blade at an angle. A fence will help you get a straight edge.
A jointer.
A handheld power jointer.
A hand plane. A good craftsman with a sharp jointer plane can do this easily.
A router table.
A handheld router.
A millwork shop can easily turn this profile out, so you can always buy it ready made, for a price.
If you have a friend with any of the above power tools, I'll bet they can be bought off for the price of a pizza.


Very much depends on what tools you have, how much money you want to spend. You can use it to justify buying a specific tool, if you have a use for one of the tools I've mentioned. They are all useful.

A tablesaw or a router are both terribly useful tools, but if this is a one time job and you have no interest in woodworking, then I'd look for a friend who can help you out. If you insist on doing it yourself, and might have an occasional use for a hand held circular saw, then go that route. A circular saw will be often enough of use even to someone who is not an avid woodworker.

Attach your board to a straight piece of wood to use as a fence. Then angle the blade, and rip the edge as you want it. I'll argue this is the cheapest solution that will give you a good edge. (A hand held jointer plane might be even cheaper, since you can get them quite inexpensively from an antique shop. But a jointer plane will take some practice to do this job well.)