Question 710517
Place the ladder of lenght L up against the wall. Then the window will be (L-1) feet high. Now place the ladder 7 feet from the base of the wall, and you get a right triangle with hypotenuse of L and two legs of 7 and (L - 1). Use the Pythagorean theorem to get
(1) L^2 = 7^2 + (L-1)^2 or
(2) L^2 = 49 + L^2 -2*L + 1 or
(3) 2*L = 50 or
(4) L = 25
Answer: The length of the ladder is 25 feet. and the window is 24 feet high.