Question

Solution of ( a picture is painted on a cardboard 20 m long and 15 cm wide such that there is a margin of 2 cm along of its sides. Find the total area of the margin)

Answer 1

${\underline{\underline{\sf{\green{ANSWER,}}}}}$

The area of margin is 124cm².

$\sf\underbrace{Explaination:-}$

Area of painted cardboard, whose dimension is 20 m by 15 m.

★ Formula using,

$\begin{gathered}\\\;\sf\orange{:\rightarrow\;\;area\; = \: \bf{{length \: \times \: breadth}\:}}\end{gathered}$

$\begin{gathered}\\\;\sf{:\rightarrow\;\;area\; = \bf{{20 \: \times \: 15}\:}}\end{gathered}$

$\begin{gathered}\\\;\sf{:\rightarrow\;\;area_(including \: margin_)\; = \bf{{300 {cm}^{2} }\:}}\end{gathered}$

★Now,

According to Question, There is a margin of 2cm along the cardboard. And we are asked to find the area of that margin. Therefore, Subtract 2cm from each side of the cardboard in order to get the area excluding Margin. (Refer to the attachment)

★ Hence,

Area of carborad excluding margin,

$\begin{gathered}\\\;\sf{:\rightarrow\;\;area\; = \bf{{16 \: \times \: 11}\:}}\end{gathered}$

$\begin{gathered}\\\;\sf{:\rightarrow\;\;area_(excluding \: margin_)\; = \bf{{176 {cm}^{2} }\:}}\end{gathered}$

★ Now,

Subtract the area of cardboard excluding margin from the Area of carborad including margin,

$\begin{gathered}\\\;\sf{:\rightarrow\;required\;area\; = \bf{{300 \: - \: 176}\:}}\end{gathered}$

$\begin{gathered}\\\;\sf{:\rightarrow\;required\;area\; = \bf{{{124cm}^{2} }\:}}\end{gathered}$

∴ The area of margin is 124cm².