Question

the perimeter of a rectangular field is 820 meters ans its area is 400meter square. find the breadth of the rectangle​

Answer 1

LET B= BREADTH AND L=LENGTH

So,

It is given that the perimeter of the rectangular field=820 m

=> 2(L+B)=820

=> 2L+2B=820.....1)

It is also given that the area of the rectangular field=400 m²

=> L×B=400.....2)

From eqn 1), the value of B=820-2L/2

Now, we have to put the value of B in eqn 2):-

=>L×B=400

=>L×(820-2L/2)=400

=>820L-2L²/2=400

=>820-2L²=400×2

=>820-2L²=800

=>-2L²=800-820

=>-2L²=-20

=>2L²=20

=>L²=20/2

=>L²=10

=>L=√10

So, L=√10

Now, putting the value of L=√10 in eqn 1):-

=>2L+2B=820

=>2×√10+2B=820

=>2√10+2B=820

=>2B=820-2√10

=>2B=813.67

=>B=813.67/2

=>B=406.835

So, LENGTH=√10 m and BREADTH=406.835 m