First post here, although I could eyeball this project I have been stumped as to how it would be calculated. I haven't been in a geometry class for nearly a decade so this really brought to light how much I have forgot. I need to find how tall a board would be cut if it descends at a certain slope for x amount of feet assuming the ground is level. I drew a diagram, basically I need to know how to solve for x, but I would like to know how it is done. Thanks for any help. EDIT: FORGOT TO MENTION IN MY DIAGRAM THAT THE ROOF PIECE THAT IS SLOPING IS 4 FT LONG, I IMAGINE THAT IS IMPORTANT.