Question

find the perimeter of a rectangular hall 30m long if length of the hall is double it's breadth​

Answer 1

Given:

• The length of a rectangular hall measures 30m
• The breadth of the hall is half of the lenh

To Find:

• The perimeter of the rectangular hall

Diagram:

◉ Rectangle--

$\setlength{\unitlength}{1cm}\begin{picture}(0,0)\thicklines\multiput(0,0)(5,0){2}{\line(0,1){3}}\multiput(0,0)(0,3){2}{\line(1,0){5}}\multiput(2.1,-0.7)(0,4.2){2}{\sf\large 30 cm}\multiput(-1.4,1.4)(6.8,0){2}{\sf\large 15 cm}\end{picture}$

Solution:

❖ Now, Here we have given the length of the rectangle which is 30m and said the the breadth of the rectangle is half times its length. So, let's find the breadth of the rectangle .

$\longrightarrow \sf\: breadth \: of \: the \: rectangle = \frac{1}{2} \times lenght \\ \\ \\ \longrightarrow \sf\: breadth \: of \: the \: rectangle = \frac{1}{ \cancel2} \times \cancel{30m} \: \: \: \\ \\ \\ \longrightarrow \sf\: breadth \: of \: the \: rectangle = { \orange{ \underline{ \boxed{ \sf{15m}}}} \bigstar} \: \: \: \:$

Henceforth,

• The breadth of the rectangle is 15

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❖ Now,let's find the perimeter of the rectangle respectively

$\star \: \blue{ \underline{ \boxed{ \pink{ \mathfrak{ perimeter \: of \:a \: rectange =2(lenght + breadth}}}}}$

After putting the values we found --

${ : \implies} \: \tt \: perimeter = 2(30 + 15) \\ \\ \\ { : \implies} \: \tt \: perimeter = 2(45) \: \: \: \: \: \: \: \: \: \: \: \\ \\ \\ { : \implies} \: \tt \: perimeter = \orange{ \boxed{ \sf{90m}}} \: \: \: \: \: \: \: \: \: \: \: \:$

Therefore :

• The perimeter of the rectangle is 90m

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Answer 2

$\large \bf \color{navy} \underline{Given} :$
➣ Length of the hall = 30m
➣ Breadth of the hall is half of it's length

$\large \bf \color{navy} \underline{To \: Find} :$
☞ Perimeter of a rectangular hall

$\huge \bf \color{navy} \underline{Solution} :$
First of all, we have to find the breadth of the rectangular hall. It is given that the length of hall is double it's breadth. So, we can say that breadth of the hall is half of it's length.

➩ Breadth of hall = $\sf\frac{1}{2} × 30 \implies \colorbox{skyblue}{15 cm}$

$\boxed{\tt \color{red}{{Perimeter \: of \: rectangle \: = \: 2(l+b) }}}$

➩ Perimeter of hall = 2(30+15)

➩ Perimeter of hall = 2× 45

➩Perimeter of hall = 90cm
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so,

$\sf \colorbox{skyblue}{Perimeter \: of \: Rectangular \: hall \: = 90cm}$
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