At the place where 8m and 4m meet, imagine that there is a line there. This creates a square and a triangle. The area of the square is easy. 8 * 8 = 64. To find the area of the triangle, use the equation (1/2)bh. (one half base times hight). The hight we already know is 4, the base we already know is 8, so now we need to plug it into the equation. 8 times 4 equals 32. Divide that by 2 and you get 16. Add that to your 64 square meters and you get 80 square meters for the full area