I'm assuming this is a right angled triangle
By Pythagoras:_
x^2 + (x + 14)^2 = 26^2 where x = length of the shortest leg
x^2 + x^2 + 28x + 196 = 676
2x^2 + 28x - 480 = 0
x^2 + 14x - 240 = 0
(x + 24)(x - 10) = 0
so shortest side x = 10 feet ( we ignore the negative root)
So the lengths of the legs is 10 and 24 feet.