Step-by-step explanation:
Given,
Perimeter of the rectangle = 200cm
Breadth of the rectangle = 10 cm
Therefore, by the problem
=> 2(l+b) = 200cm
=> 2(l + 10) = 200cm
[tex] = > l + 10 = \frac{200}{2} [/tex]
=> l + 10 = 100
=> l = 100 - 10
=> l = 90
Hence, required length othe rectangle is 90 cm (Ans)