Pedro animal has the shape of a horse. The animal is made up of different shapes, we can see that the shapes Pedro animal is made up of consist of two triangles, three rectangles and a hexagon.
All this shapes mentioned above (triangle, rectangle and hexagon) that are used in making this animal have sides with straight edges. Therefore the sides of all the shapes are straight.
Let be the surface of the rectangular prism bounded by the planes , , , , , and . By the divergence theorem, the integral of over is given by the integral of over the interior of (call it ):