Build shelfing for a closet and an angled wall (trapezoid)

I have a closet in out second bedroom with 1 angled wall. There isn't currently any shelving in there. So quite deep so I'm hoping to to build some shelves into it to make the most of all the wasted space. I'm hoping someone cal help me figure out the way to nite down the side and shape of the space so that I can ask my local hardware to cut some pieces to size. Thanks !