Question

The length of a rectangle is three times the breadth. If the minimum perimeter of the rectangle is $160cm$, then

• A. breadth $>20cm$
• B. length $<20cm$
• C. breadth $\ge 20cm$
• D. length $\le 20cm$

Answer 1

Answer: (C)

Let breadth of rectangle be $xcm$.
$\therefore \text{ Length of rectangle }=3x$
$\text{ Perimeter of rectangle }=2(\text{ Length }+\text{ Breadth })$
$=2(x+3x)=8x$
$\text{ Given, }\text{ Perimeter }\ge 160cm$
$8x\ge 160$
Dividing both sides by 8 ,
$x\ge 20cm$