Answer:
The sum of the lengths of the sides is 2292 yards and the sum of the lengths of the triangle is 3056 yards
Explanation:
Since y represents the length of fence that is opposite (parallel) to the river and x represent the length of fence perpendicular to the river.
Therefore since we can use 3,056 yards of fencing
Side perpendicular to the river = x and,
Side opposite to the river = y = 3056 - 2x
The area of the rectangle formed (A) = Perpendicular side × Parallel side
∴ A = x(3056 - 2x) = 3056x - 2x²
A = 3056x - 2x²
To maximize the area, A' (dA/dx) = 0
∴ A' = 3056 - 4x = 0
3056 - 4x = 0
4x = 3056
x = 764 yards
y = 3056 - 2x = 3056 - 2(764) = 1528 yards.
Side perpendicular to the river = 764 yards and,
Side opposite to the river = 1528 yards
The sum of the lengths of the sides = 764 + 1528 = 2292 yard and the sum of the lengths of the triangle = 764 + 764 + 1528 = 3056 yards
