Johnny357 said:
I have a table who's top is 36.75 in. wide, I want the table to be 30 in. tall but, I want the legs to be crossed how do I find the length of the table legs keep in mind that the leg is a 2X4 and i also need to find the angle of the cut to keep the leg flush anginst the table. The 2X4 is actully 1 7/8X3 3/4.
I'm going to assume that we don't care about the 1+7/8 side of the 2x4, since you're going to place the legs with the 3¾ side vertical, right? Also, the legs won't be sticking out, right? This is for a REAL table, right? If it's a homework assignment, I'd give an entirely different answer.
The figure I imagine is a parallelogram. It has small horizontal edges and much longer diagonal edges. One horizontal edge is against the bottom of the table top and the other horizontal edge is on the ground.
The first chunk of information is easy. It's just the Pythagorean Theorem:
30"<sup>2</sup> + 36.75"<sup>2</sup> = Z<sup>2</sup>, where Z is the diagonal between the two most distant corners, the edge of the table on one side and the ground on the other side.
Z = 47.4401" = apprx (47 + 14/32)" -- Just a hair more
With a little work, it can be determined that the angle you need to cut is 43.7595º. If you can cut that angle and measure the 47.4401", you're done.
If you can't cut that angle, you'll have to measure something else.
1) Suffice it to say that you'll need a piece of lumber 44.4755" = apprx (44 + 15/32)" -- a little bit more.
2) From the GROUND end of the board, along the TOP edge, measure 3.9160" = apprx (3 + 29/32)" -- a bit more, actually.
3) From that point, construct a perpendicular to the bottom edge.
4) You should be able to measure from the point on the bottom edge back to where you started, a distance of 5.4220" = apprx (5 + 13/32) -- again, a little more. Make this cut after checking your measurements 12 times.
5) Do the same thing on the TABLE end, but start on the BOTTOM edge, constructing the perpendicular to the top edge.
I rounded to 1/32" and ignored the width of the saw blade. Your carpentry skills will have to compensate for those two items.