How to measure the land in sq.feet?

I would divide it into rectangles and triangles, if that makes sense. You can make it into a rectangle that is 50 x 63 and you already know the area of that. Then you are left with some triangles on the sides. They might be (depending on the actual shape) something like 5 base by 2 height. Remember that the area of a triange is base x height divided by 2. Even if you have more than 1 triangle after you find your rectangle, you can calculate all their areas. Then, just add up all the little areas that you calculate. Good luck!