the picture in the attached figure
we know that
In a square pyramid we have five faces, 4 triangles and 1 square. So to determine surface area we need to take the areas of the triangles and square and add them all up
The square's area is relatively simple:A=b²
A=6²=36 ft²But now let's observe the triangles, a triangle's area is:
A=(1/2)*b*hthe base is equal to 6 ftb=6 ftAC=BC----------> because the angle is 45°AC=6 ft/2----> 3 ftsoBC=3 ftA=(1/2)*6*3----> 9 ft²
Multiply the triangle's area by four to account for all four triangular faces and add the squares area for your answer
Surface area=36 +4*9-----> 72 ft²the answer is
72 ft²