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The Area of a Rectangular is 640 M2. Taking Its Length as X Cm; Find in Terms of X, the Width of the Rectangle. If the Perimeter of the Rectangle is 104 M; Find Its Dimensions. - Mathematics

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Question

The area of a rectangular is 640 m2. Taking its length as x cm; find in terms of x, the width of the rectangle. If the perimeter of the rectangle is 104 m; find its dimensions.

Sum

Solution

Let b be the width of the rectangle.
`x` x b = 640

b = `640/x`

Again perimeter of the rectangle is 104 m.
Hence,
`2( x + 640/x )` = 104

x2 - 52x + 640 = 0
( x - 32 )( x - 20 ) = 0
x = 32, 20.

Hence
length = 32 m
width = 20 m.

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Chapter 20: Area and Perimeter of Plane Figures - Exercise 20 (B) [Page 256]

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Selina Concise Mathematics [English] Class 9 ICSE
Chapter 20 Area and Perimeter of Plane Figures
Exercise 20 (B) | Q 29 | Page 256

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