Given,
Perimeter = 82 m and its area = 400 m2
Let the breadth of the rectangle be considered as x m.
We know that,
Perimeter of a rectangle = 2(length + breadth)
82 = 2(length + x)
41 = (length + x)
⇒Length = (41 – x)m
We also know that,
Area of the rectangle = length x breadth
400 = (41 – x)(x)
400 = 41x – x2
x2 – 41x + 400 = 0
x2 – 25x – 16x + 400 = 0
x(x – 25) – 16(x – 25) = 0
(x – 16)(x – 25) = 0
Now, either x – 16 = 0 ⇒ x = 16
Or, x – 25 = 0 ⇒ x = 25
Therefore, the breadth of the rectangle can be either 16 m or 25 m respectively.