Answer:
8 by 8.
Step-by-step explanation:
A triangular sail to be constructed with a vertical and a horizontal poles for support. The combined weight of the poles cannot exceed 80 pounds and the poles weigh 5 pounds per foot gives us a total length of 80/5=16 feet. Let us call the length of horizontal pole by x and we have (16-x) for the vertical one. We want to maximize area of the sail, so [tex] A(x)= x (16-x)/2 [\tex] is the function we want to maximıze on [0, 16].