in order to solve this you have to use the pythagorean’s theorem, which is a^2+b^2=c^2. from the problem you can find out you have a=13ft and c=24ft. c is your hypotenuse. you then solve and you get b=20.17ft. you can check to make sure the answer is right, but that is how you solve it. And the ladder would reach 20.17ft.
