Question

Enclosing the Largest Area The owner of the Rancho Grande has 3,052 yd of fencing with which to enclose a rectangular piece of grazing land situated along the straight portion of a river. If fencing is not required along the river, what are the dimensions (in yd) of the largest area he can enclose

Answer 1

the shorter side = 1526

the longer side = 763

area = 1164338

Explanation:

lets say

a=length

b = width

a + 2b = 3052

this is the perimeter

such that

a = 3052 - 2b

the area of a rectangle is a*b

= (3052 - 2b)b

= 3052b - 2b²

we differentiate this to get:

= 3052 - 4b

such that

3052 = 4b

divide through by 4, to get b, the width

3052/4 = 763

b = 763

put the value of b into a

a = 3052 - 2b

a = 3052 - 2(763)

a = 3052 - 1526

a = 1526

therefore

the shorter side = 1526

the longer side = 763

area = a x b

area = 1526 x 763

area = 1526 x 763

= 1164338