You can
put this solution on YOUR website!first of all, let's solve for (x+3)^2
(x+3)(x+3)
x(x+3)+3(x+3)
x^2+3x+3x+9
x^2+6x+9
Then put this into the equation
x^2+x^2+6x+9=225
2x^2+6x+9=225
Now subtract both sides by 225 to make both sides equal to zero
2x^2+6x-216=0
Use the quadratic formula

x=(-48/4) or (36/4)
x=-12 or 9
Since length cannot be negative number, -12 is not the answer, so 9 is the length of the shorter leg.
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check: 9^2+(9+3)^2=225
81+144=225
225=225 (correct!!!)