What's the noun for bevel? Here's the word you're looking for.
bevel
An edge that is canted, one that is not a 90 degree angle; a chamfer.
An instrument consisting of two rules or arms, jointed together at one end, and opening to any angle, for adjusting the surfaces of work to the same or a given inclination; a bevel square.
“You must cut the board at a 10-to 15-degree bevel so you can insert the groove over the last tongue and pivot the other edge of it into place without damaging the adjacent wall.”
