Answer
385.5k+ views
Hint: We are given the dimensions of the rectangular field and assuming the width of the path around it to be x we get the dimensions of the new rectangle to be $20 + 2x$m and $14 + 2x$m and it's clear that the area of the path is equal to the difference of the areas of the rectangles hence we find the area of the rectangles using the formula $Area = l\times b$ and further equating the area of the path with difference we get the value of x.
Complete step by step solution:
We are given the length and width of a rectangular field to be 20 m and 14 m
Now we are given that there is a path around the field with equal width
Let the width of the path be x
Now from the diagram we can see that now the length and breadth of the new rectangle is $20 + 2x$m and $14 + 2x$m respectively.
We are given the area of the path that is the area of the shaded region is 111 sq.m.
This area is obtained by subtracting the area of the small rectangle from the area of the big rectangle
We know that the length and breadth of the small rectangle is 20 m and 4 m respectively.
Hence the area of the small rectangle is given by
$
\Rightarrow Area = l\times b \\
\Rightarrow Area = 20\times 14 \\
\Rightarrow Area = 280{m^2} \\
$
We know that the length and breadth of the big rectangle is $20 + 2x$m and $14 + 2x$m respectively
Hence the area of the big rectangle is given by
$
\Rightarrow Area = l\times b \\
\Rightarrow Area = \left( {20 + 2x} \right)\left( {14 + 2x} \right) \\
\Rightarrow Area = 280 + 40x + 28x + 4{x^2} \\
\Rightarrow Area = \left( {280 + 68x + 4{x^2}} \right){m^2} \\
$
Now since
Area of the path = the difference between the areas of the rectangles
$
\Rightarrow 111 = 280 + 68x + 4{x^2} - 280 \\
\Rightarrow 111 = 68x + 4{x^2} \\
\Rightarrow 4{x^2} + 68x - 111 = 0 \\
\Rightarrow 4{x^2} - 6x + 74x - 111 = 0 \\
\Rightarrow 2x\left( {2x - 3} \right) + 37\left( {2x - 3} \right) = 0 \\
\Rightarrow \left( {2x - 3} \right)\left( {2x + 37} \right) = 0 \\
\Rightarrow x = \dfrac{3}{2},\dfrac{{ - 37}}{2} \\
$
Since the width cannot be negative we take the value of x to be $\dfrac{3}{2}$m
Therefore the width of the path is $\dfrac{3}{2}$m.
Note :
Many students tend to write the dimension of the new triangle to be 20 + x and 14 + x
But since the width is added on both sides we need to add 2x on both sides.
Complete step by step solution:
We are given the length and width of a rectangular field to be 20 m and 14 m
![seo images](https://www.vedantu.com/question-sets/98b8b0ca-c1ca-4db4-a917-e6dc164c5d677375696540031798748.png)
Now we are given that there is a path around the field with equal width
Let the width of the path be x
Now from the diagram we can see that now the length and breadth of the new rectangle is $20 + 2x$m and $14 + 2x$m respectively.
![seo images](https://www.vedantu.com/question-sets/cc0527a9-1168-462d-a021-d829c04b2f964297653027521353876.png)
We are given the area of the path that is the area of the shaded region is 111 sq.m.
![seo images](https://www.vedantu.com/question-sets/46832a98-b86d-4dd5-92cd-1e5950053c3a8457510855588748040.png)
This area is obtained by subtracting the area of the small rectangle from the area of the big rectangle
We know that the length and breadth of the small rectangle is 20 m and 4 m respectively.
Hence the area of the small rectangle is given by
$
\Rightarrow Area = l\times b \\
\Rightarrow Area = 20\times 14 \\
\Rightarrow Area = 280{m^2} \\
$
We know that the length and breadth of the big rectangle is $20 + 2x$m and $14 + 2x$m respectively
Hence the area of the big rectangle is given by
$
\Rightarrow Area = l\times b \\
\Rightarrow Area = \left( {20 + 2x} \right)\left( {14 + 2x} \right) \\
\Rightarrow Area = 280 + 40x + 28x + 4{x^2} \\
\Rightarrow Area = \left( {280 + 68x + 4{x^2}} \right){m^2} \\
$
Now since
Area of the path = the difference between the areas of the rectangles
$
\Rightarrow 111 = 280 + 68x + 4{x^2} - 280 \\
\Rightarrow 111 = 68x + 4{x^2} \\
\Rightarrow 4{x^2} + 68x - 111 = 0 \\
\Rightarrow 4{x^2} - 6x + 74x - 111 = 0 \\
\Rightarrow 2x\left( {2x - 3} \right) + 37\left( {2x - 3} \right) = 0 \\
\Rightarrow \left( {2x - 3} \right)\left( {2x + 37} \right) = 0 \\
\Rightarrow x = \dfrac{3}{2},\dfrac{{ - 37}}{2} \\
$
Since the width cannot be negative we take the value of x to be $\dfrac{3}{2}$m
Therefore the width of the path is $\dfrac{3}{2}$m.
Note :
Many students tend to write the dimension of the new triangle to be 20 + x and 14 + x
But since the width is added on both sides we need to add 2x on both sides.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Why Are Noble Gases NonReactive class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let X and Y be the sets of all positive divisors of class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Which are the Top 10 Largest Countries of the World?
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write a letter to the principal requesting him to grant class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Give 10 examples for herbs , shrubs , climbers , creepers
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Fill in the blanks A 1 lakh ten thousand B 1 million class 9 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Change the following sentences into negative and interrogative class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference Between Plant Cell and Animal Cell
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)