Question

A rectangular park of perimeter 320 & area 4800 if so find it's length & breadth

Answer 1

Answer:

Length = 120 units

Breadth = 40 units

Step-by-step explanation:

let the length = x

and breadth = y

Area of park= length × breadth

=>4800 = xy ---> (i)

Perimeter of park = 2(x + y)

=>320 = 2x + 2y

=>160 = x + y

=>y = 160 - x ----> (ii)

From eqn (i) :

=>xy = 4800

=> x(160-x) = 4800 {from eqn (ii) }

=> 160x - x² = 4800

=> x² - 160x + 4800 = 0

=> x= 160±√(-160)² - 4(4800)/2

=> x= 160±√25600 - 19200/2

=> x= 160±√6400/2

=> x= 160±80/2

=> x= 160 + 80/2 ; 160 - 80/2

=> x= 240/2 ; 80/2

=> x= 120 ; 40

Now taking x= 40 ,we get:

=>y = 160 - x

=>y = 160 - 40

=>y = 120 {Since, breadth is greater than length, So we take x = 120}