[Surface area ]=[the area of 4 triangles]+[the area of square base] [the area of square base]=8*8--------> 64 ft²
[the area of 1 triangle]=(1/2)*b*h b=8 ft How the angle is 45°-------> h=b/2-------> h=4 ft then [the area of 1 triangle]=(1/2)*8*4------> 16 ft² and [the area of 4 triangles]=4*16--------> 64 ft²
[Surface area ]=[64 ft²]+[64 ft²]----------> 128 ft²
