Question

ASAP HELP PLEASE:
This image shows a square pyramid. What is the surface area of this square pyramid?

a. 32 ft^2
b.64 ft^2
c. 128 ft^2
d. 136 ft^2

Answer 1

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