To find the surface area, we need to find the area of all the sides. There are five sides, but four of them are exactly the same.
To find the area of a triangle, you need to do width x height / 2. The width is five and the height is eight. 5 x 8 / 2 = 20. There are three more sides that have the exact same area as this. Since there are four sides that have a surface area of twenty, we do 20 x 4 = 80. Then, we find the area of the bottom piece. To find the area of a square, you need to do length x width. 5 x 5 = 25. Then, we add our two areas to get the final result. 80 + 25 = 105. Therefore, 105 is the surface area of the pyramid.
