Question

The area of a rectangle is 200 metre square .If the length is twice the breadth .What is the perimeter of rectangle?

Answer 1

Step-by-step explanation:

breath of rectangle = b cm

length of rectangle = 2b cm

area of rectangle = 200cm²

l×b = 200

2b×b = 200

2b² = 200

b² = 100

b = 10cm

perimeter of rectangle = 2(l+b)

= 2(20+10)

= 2(30)

= 60cm

Answer 2

Given :

• The area of a rectangle is 200 m square .
• The length is twice the breadth.

To find :

• Perimeter of the rectangle.

Solution :

Consider,

• Length of the rectangle = x m
• Breadth of the rectangle = y m

According to the condition :-

• The length is twice the breadth.

$\implies\sf{x=2y..............eq[1]}$

According to the question,

$\implies\sf{xy=200}$

$\implies\sf{2y^2=200\:[put\:x=2y\: from\:eq[1]}$

$\implies\sf{y^2=100}$

$\implies\sf{y=\sqrt{100}}$

$\implies\sf{y=10}$

• Breadth = 10 m.

Now put y = 10 in eq (1).

$\implies\sf{x=2y}$

$\implies\sf{x=2\times\:10}$

$\implies\sf{x=20}$

• Length = 20 m

Perimeter = 2(20+10) m

→ Perimeter = 60 m

Therefore, the perimeter of the rectangle is 60 m.