There are 4 triangles and the formula for the area of a triangle is 1/2BH so 11x10 is 110 and then take half of that and you’ll get 55. Since there are 4 triangles you need to then multiply that by 4 to get 220. And then you have to find the area of the square base which is 11x11 which will come out to 121. So you add the 220 and 121 to get 341.