The slope is the slope :D
4.75 feet, because you would multiply 5 by 1.54 which gives you 7.25 subtract that from 12
I believe it is 960 inches. For the long triangles, I just made them a square so I multiplied base times height. For the small triangles, i did the same thing. Long triangles were 640, small triangles were 320
I would advise you to use the website desmos