If you mean a miter cut, the length of the miter is

the root of two times the square of the width of the board.

If you mean a bevel cut, the length of the bevel is

the root of two times the square of the thickness of the board.

1 inch wide =3D 1.4142135623730950488016887242097
2 inch wide =3D 2.8284271247461900976033774484194
3 inch wide =3D 4.24264068711928514640506617262909
4 inch wide =3D 5.65685424949238019520675489683879

It appears the bevel/miter is proportional to the width by a factor of =
~1.41.
Or, the width/thickness is always 70.7106781186547524400844362105198% of =
the bevel/miter.

--=20

PDQ
--
=20
"David" wrote in message =
...
| I've got a board set at a 45 degree angle, back from a line. How much =

| (percentage) of the length of the board does it take up? To=20
| conceptualize the issue, I drew a one inch line on paper with a ruler, =

| and rotated the ruler to a 45 degree angle, thinking that the one inch =

| mark on the ruler would be only 1/2 away from the starting point =
(along=20
| the original path of the ruler), but it looks like it's about 90% =
along=20
| the one inch span. What's the formula?
|=20
| Dave