All of the references give a method of drawing an ellipse using the two foci and some string. I have found this method suitable only for drawing jelly bean or kidney shapes.
The thingy you’ve got to build lies diagonally across a raked deck. How do you figure out the length, angle and bevel so that it sits vertically?
Where the rake is the combination of two angles the actual slope of the rake is a transcendent trigonometric function of those two angles. I ran off with the theater to avoid having to deal with algebra; and Trig is Algy’s bigger, meaner older brother.
What are the dimensions of the opening required to pass a cylindrical object through an inclined plane?
What do you do when you have to equally divide a line with an awkward (39-5/16”) or unknown length into a difficult number of parts (7)?
I’ve been tossing around terms like; erect a perpendicular, strike an arc; geometry. Unlike what you may have thought in Middle School; Geometry is your friend.