Question 450092
{{{x^2+(x+7)^2=(x+9)^2}}}
{{{x^2+x^2+14x+49=x^2+18x+81}}}
{{{x^2-4x-32=0}}}
{{{(x-8)(x+4)=0}}}
{{{x=8 or -4}}}
Throwing out the negative answer, we get the short leg to be 8ft., the long leg to be 15ft., and the hypotenuse to be 17ft..