Question

The area of a rectangle is 460 m² and its breadthis 20 m. Find the perimeter of the rectangle.
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Answer 1

Answer:

 Breadth = 20 meter

We know that the area of a rectangle is the product of length and breadth. Thus,

Area A of the rectangular plot = Length x Beadth …………………………………….(1)

Given, length is 15% more than the breadth.

That is, Length = Breadth + (15/100) breadth

= Breadth + .15 x Breadth = (1.15)Breadth

∴ A = 1.15 x Breadth x Breadth = 1.15 x (Breadth)² ………………………………….…(2)

Given, A = 460 square meters

Substituting in (2),

460 = 1.15 (Breadth)²

Or, 460/1.15 = 1.(Breadth)² [Dividing both sides by 1.15]

Or, (Breadth)² = 460/1.5 = 400 = 20² square meter

Taking square root,

Breadth = ±20 meter

Since length is always a positive quantity, we discard the negative value to get

Breadth = 20 meter.

Answer 2

Step-by-step explanation:

Breadth(b)=20m

Area=l×b=460m²

=>l=460÷20

=>l=23m

Perimeter=2×(l+b)

=2×(23m+20m)

=84m