we know that
surface area of the square pyramid=area of the base+4*[area of lateral triangle]
area of the base=b²----> area of square
b=6 ft
area of square=6*6---> 36 ft²
area of lateral triangle=b*h/2
b=6 ft
h=9 ft
area of lateral triangle=6*9/2---> 27 ft²
surface area of the square pyramid=36+4*27----> 144 ft²
the answer is
144 ft²