Please show me how to do word problem?

So since you know it's a right triangle, you can use the Pythagorean Theorem (a^2 + b^2 = c^2). I hope you know that the longest leg is always the hypotenuse (c). So let's say that the third leg is x. That makes the second leg x+4 because its 4 feet longer than the third one which is x. So if you plug that into the formula, you get (x)^2 + (x+4)^2 = 6^2. When you foil the second part, you'll get x^2 + x^2 + 8x + 16 = 36. Combine like terms and you'll get 2x^2 + 8x - 20 = 0. You can't factor so plug it into the Quadratic Formula. Simplify and you'll get that answer. You can check yourself with a calculator. Hope this helped!