Answer
353.2k+ views
Hint: Here we go through by assuming the diagram of cuboid and then apply the formula of area of four walls of cuboid then put the values that are given in the formula then find out the unknown terms.
Complete step-by-step answer:
First method
For clear understanding what the area of 4 walls of cuboid is we draw its diagram.
Here the area of 4 walls of cuboid means the sum of the area of face, ADEF, CDEH, BCGH and ABFG.
And we see that these faces are in the shape of a rectangle in which the face ADEF and face BCGH are the same with length =8cm and breadth= b and the other two faces CDEH and ABFG are same with length l= 18cm and height h= 8cm.
And we know that area of rectangle is $l \times b$
Then for the area of face ADEF and face BCGH we apply this formula we get,
Area of face ADEF and face BCGH $ = 2 \times 8 \times b = 16b{\text{ }}c{m^2}$
Similarly area of faces CDEH and ABFG$ = 2 \times 18 \times 8 = 288{\text{ }}c{m^2}$
And the total area of these four surfaces is given as 448$c{m^2}$
i.e. 16b+288=448$c{m^2}$
$
\Rightarrow 16b = 448 - 288 \\
\Rightarrow b = \dfrac{{160}}{{16}} = 10cm \\
$
Second method
And the simple method that we use generally is by applying the formula of area of 4 walls of cuboid i.e. $2(l + b) \times h$.
Area of 4 walls of cuboid=$2(l + b) \times h$
After putting the values in formula we get,
$
\Rightarrow 448 = 2(18 + b) \times 8 \\
\Rightarrow 224 = 18 \times 8 + 8b \\
\Rightarrow 224 - 144 = 8b \\
\Rightarrow b = \dfrac{{80}}{8} = 10cm \\
$
Hence the breadth is equal to 10 cm.
Note: Whenever we face such type of question the key concept for solving the question is just simply put the formula of the area of 4 wall of cuboid and put the terms that are given in the question and find out the unknown terms form that formula and whenever you forgot the formula you can solve as in that manner that I solve in first method.
Complete step-by-step answer:
First method
For clear understanding what the area of 4 walls of cuboid is we draw its diagram.
![seo images](https://www.vedantu.com/question-sets/05759d1f-c325-4407-bd38-7a09651c43387235908773194678016.png)
Here the area of 4 walls of cuboid means the sum of the area of face, ADEF, CDEH, BCGH and ABFG.
And we see that these faces are in the shape of a rectangle in which the face ADEF and face BCGH are the same with length =8cm and breadth= b and the other two faces CDEH and ABFG are same with length l= 18cm and height h= 8cm.
And we know that area of rectangle is $l \times b$
Then for the area of face ADEF and face BCGH we apply this formula we get,
Area of face ADEF and face BCGH $ = 2 \times 8 \times b = 16b{\text{ }}c{m^2}$
Similarly area of faces CDEH and ABFG$ = 2 \times 18 \times 8 = 288{\text{ }}c{m^2}$
And the total area of these four surfaces is given as 448$c{m^2}$
i.e. 16b+288=448$c{m^2}$
$
\Rightarrow 16b = 448 - 288 \\
\Rightarrow b = \dfrac{{160}}{{16}} = 10cm \\
$
Second method
And the simple method that we use generally is by applying the formula of area of 4 walls of cuboid i.e. $2(l + b) \times h$.
Area of 4 walls of cuboid=$2(l + b) \times h$
After putting the values in formula we get,
$
\Rightarrow 448 = 2(18 + b) \times 8 \\
\Rightarrow 224 = 18 \times 8 + 8b \\
\Rightarrow 224 - 144 = 8b \\
\Rightarrow b = \dfrac{{80}}{8} = 10cm \\
$
Hence the breadth is equal to 10 cm.
Note: Whenever we face such type of question the key concept for solving the question is just simply put the formula of the area of 4 wall of cuboid and put the terms that are given in the question and find out the unknown terms form that formula and whenever you forgot the formula you can solve as in that manner that I solve in first method.
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)