Question

find the dimensions of a rectangle whose perimeter is 28 metres and whose area is 40 square metres​

Answer 1

Step-by-step explanation:

Given,

Perimeter of rectangle = 28

2(l+b)= 28

l + b = 14

l = 14-b .....(1)

Area = 40

l × b = 40

from equ...(1)

(14-b)×b=40

(14-b^)=40

b^-14b+40=0

b^ -4b -10b+40=0

b(b-4)-10(b-4) =0

b-4=0 b-10= 0

b=4 b = 10.

therefore, length of rectangle = 10

breath of rectangle = 4

Answer 2

Given,

Perimeter of rectangle = 28

2(l+b)= 28

l + b = 14

l = 14-b .....(1)

Area = 40

l × b = 40

from equ...(1)

(14-b)×b=40

(14-b^)=40

b^-14b+40=0

b^ -4b -10b+40=0

b(b-4)-10(b-4) =0

b-4=0 b-10= 0

b=4 b = 10.

therefore, length of rectangle = 10

breath of rectangle = 4