I have very minimal fabrication tools for metalwork,  basically a chopsaw and a drill press. The angle of the upper support structure was the most complicated part of the stump stand assembly. On the food cart I had drawn the roof on my CAD software and then measured the angle in the program. In designing the stump stand I wanted it to be a nine foot cube with a two foot tall peak to strengthen the hitch point. I knew that with some trigonometry, which I have never studied, I could compute the angle by knowing all the lengths. The question was how and by what means? My normal recourse would be to draft a triangle of the dimensions in the software, but why not try to scratch it out on the shop floor, I thought. I consulted wikipedia and other sites, then cut 2 successive pipes at the wrong angle. OK, I realized I did need to draft it out. Once I had done that and manually measured the angle, I went back and figured out the formula. Turns out I was looking for the sine, which is the ratio of the opposite to the hypotenuse in a right triangle, and it reads out in radians. A  degree is simply 0.07 radians or something like that. That was kindav fun, learning some trig. So on the third try I got the angles right! It turns out I was doing it correctly but didn't understand the difference between measuring a circle in degrees versus radians or something like that.