Answer :
By the pythagorean theorem:
L^2=9^2+x^2
and we are told if:
L^2=(x+3)^2
L=x+3
L-3=x now using this in our first equation L^2=9^2+x^2 we get
L^2=9^2+(L-3)^2
L^2=81+L^2-6L+9
0=90-6L
6L=90
L=15 ft
L^2=9^2+x^2
and we are told if:
L^2=(x+3)^2
L=x+3
L-3=x now using this in our first equation L^2=9^2+x^2 we get
L^2=9^2+(L-3)^2
L^2=81+L^2-6L+9
0=90-6L
6L=90
L=15 ft