Width=w
length=(40-2w)/2=20-w
A=w(40-w)
A=40w-w²
A'=40-2w=0
2w=40
w=20

20x20 is the size of the pen having the greatest area. this tells us the largest rectangle for a given perimeter is a square

8 0

2 years ago

The length and breadth of rectangular field are 240m and 200m respectively. Find the cost of digging the field at Rs 10 per m^2

Inga [223]

Answer:

Please check the explanation.

Step-by-step explanation:

Given

The length of rectangular field = l = 240m

The breadth of rectangular field = w = 200m

We can determine the area of the rectangular field using the equation

$A=wl$

where

$l$ is the length

$w$ is the width

substituting l = 240m, and w = 200m in the formula

$A=wl$

A = 240 × 200

A = 48000 m²

Given that the cost of digging the field at Rs 10 per m².

Thus,

The cost of digging the field of the area 48000 m² = 10 × 48000

= 480000 Rs

Therefore, the total cost of digging = 480000 Rs

8 0

3 years ago