Let h be the height to which latter of length of 20 ft reach then using Sine formula in right triangle with hypotenuse 20 & vertical leg h & opposite acute angle 0 = 72∘ sin θ =h 20 sin 72∘= h 20
X is always dependant to Y. so that should answer the 1st one. the 2nd looks to be around 17-18. 17.5 maybe. and the 3rd is yes cause he does not go to the pool so it isnt any cost.
