A veterinary clinic plans to build four identical dog kennels along the side of its building using 210 feet of fencing. (See the picture.) What should be the dimensions of each kennel to maximize the enclosed area? (Note: No fencing is needed along the side of the building.

Answer 1

5x + 4y = 210 ... 4y = 210 - 5x

A = 4 x y = x (210 - 5x) = 210x - 5x^2

max A on axis of symmetry
... x = -210 / (2 * -5) = 21

Answer 2

26.25 feet and 21 feet :P