A college is planning to construct a rectangular parking lot on land bordered on one side by a highway. The plan is to use 520 feet of fencing to fence off the other three sides. What dimensions should the lot have if the enclosed area is to be a maximum?

step-by-step explanation: step 3 should really go to step seven, but anyway never mind.

1 ∠oln ≅ ∠lno

  or  

sin y = 7/q

7 is the opposite side length, q is the hypotenuse

tan y = 7/r

7 is the opposite side length, r is the adjacent side length

using sohcahtoa ^^^^

cos y = adjacent/hypotenuse

cos y = r/q