This is part of a homework question
I'm trying to figure out the perimeter of the black-filled object below (sorry, it's crudely drawn in paint, but I think you get the idea). To find the perimeter, I'm assuming that I should first find the perimeter of the rectangle (12*2+3*2 in this case) then subtract each little triangle (which is suppose to be all the same size by the way). The question mentions only one fact other than the size of each side- that it's trisected. I'm pretty sure the answer to this question lies in here...