Question

plz solve this problem. ​

Answer 1

SOLUTION :-

=> Let the length and breath of the park be l and b.

=>Perimeter = 2(l+b)

=> 80 = 2(l+b)

=>80 = 2l + 2b ------(divide by 2)

[We get, ]

=> 40 = l + b

=>.°. b = 40 - l.

=> Area = l × b

=> Area = l(40-l)

=> .°. Area = 40l - l².

=> .°. 40l - l² = 400

=>l²-40l +400 = 0

=>Comparing with this equation al²+bl+c = 0 .

=>We obtain, a = 1 , b = -40 , c = 400.

=>Discriminate = b²-4ac

=> D = (-40)²-4(1)(400)

=>D = 1600 - 1600

=>.°. D = 0

=> As b²-4ac=0

=>Therefore, this equation has real roots . And hence, this situation is possible.

=> Root of the equation,

=> l = -b/2a

=> l = -(40)/2(1)

=> l = 40/2

=> .°. l = 20m.

Therefore,

=> The length of park 20m.

=> And breath of park = 40-l = (40-20)m = 20m.