This image shows a square pyramid. what is the surface area of this square pyramid? a. 32 ft² b. 64 ft² c. 128 ft² d. 136 ft²

We know that

[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

the answer is 128 ft²