Perimeter = 2(Length) + 2(Width)
300 = 2L + 2W → 150 = L + W → 150 - L = W
Area = Length · Width
= L(150 - L) →
= 150L - L²
There are 2 different methods for solving (depending on which math course you are taking).
<u>Calculus</u>: find the derivative, set it equal to zero, and solve for L.
= 150L - L² → 0 = 150 - 2L → 2L = 150 → L = 75
<u>Algebra</u>: find the vertex.
= - L² + 150L → L = -b/2a → L = -150/2(-1) → L = 75
Once you solve for L, plug it into the Perimeter equation to solve for W:
150 - L = W → 150 - 75 = W → W = 75
Answer: 75ft x 75ft