Question

Find the area of the circle whose diameter is 42 cm​

Answer 1

Answer:

5544cm²

Step-by-step explanation:

diameter = 42 cm

radius = diameter /2

= 42/2

radius = 21 cm.

we know that ,

area of circle = 4πr²

= 4×22/7×(21)²

=4×22/7×21×21

=4×22×21×3

=5544cm².

The area of the circle of diameter 42cm

= 5544cm²

Answer 2

$\star \; {\underline{\boxed{\red{ \pmb{\pmb{\frak{ \; Given\; \; :- }}}}}}}$

• Diameter = 42cm

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• Area Of The Circle = ?

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$\begin{gathered}\begin{gathered}\begin{gathered} \\ \\\end{gathered}\star \;{\underline{\boxed{\green{\pmb{\frak{ \;Solution\; :- }}}}}}⋆\end{gathered}\end{gathered}$

$\maltese$  Formula Used :

• ${\underline{\boxed{ \pmb{ \pmb{ \pmb{\pmb{\sf{Area_{(Circle)}=4\pi \: r^2}}}}}}}}$

$\begin{gathered}\begin{gathered} \\ \\\end{gathered}\begin{gathered}\begin{gathered} \\\qquad{\rule{200pt}{2pt}} \end{gathered}\end{gathered}\end{gathered}$

Where :

• R = Radius

$\begin{gathered}\begin{gathered} \\ \\ \end{gathered}\end{gathered}$

✠  Calculating The Area :

$\begin{gathered}\begin{gathered} \\ \\\end{gathered}\end{gathered}\begin{gathered} \qquad \;\dashrightarrow \; \;\sf{Area_{(Circle)}=4 \pi r^2}\end{gathered}$

$\begin{gathered}\begin{gathered} \\ \\\end{gathered}\end{gathered}\begin{gathered} \qquad \; \dashrightarrow \; \;\sf{Area_{(Circle)}=4 \times \: \dfrac{22}{7} \: \times r^2}\end{gathered}$

$\begin{gathered}\begin{gathered} \\ \\\end{gathered}\end{gathered}\begin{gathered} \qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4 \times \:\dfrac{22}{7} \:\times\dfrac{Diameter {}^{2} }{2} }\end{gathered}$

$\begin{gathered}\begin{gathered} \\ \\ \end{gathered}\end{gathered}\begin{gathered} \qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4 \times \: \dfrac{22}{7} \: \times \dfrac{42 {}^{2} }{2} }\end{gathered}$

$\begin{gathered} \qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4 \times \: \dfrac{22}{7} \: \times \cancel\dfrac{42 {}^{2} }{2} }\end{gathered}$

$\begin{gathered} \qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4 \times \: \dfrac{22}{7} \: \times 21 {}^{2} }\end{gathered}$

$\begin{gathered} \qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4 \times \: \dfrac{22}{7} \: \times 21 \times 21 }\end{gathered}$

$\begin{gathered} \qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4 \times \: \dfrac{22}{7} \: \times 441 }\end{gathered}$

$\begin{gathered}\qquad \; \dashrightarrow\; \; \sf {Area_{(Circle)}=4\times \: \dfrac{22}{ \cancel7} \:\times\cancel{441}}\end{gathered}$

$\begin{gathered} \qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4\times \: 22\:\times63}\end{gathered}$

$\begin{gathered}\qquad \; \dashrightarrow \; \; \sf {Area_{(Circle)}=4 \times \: 1386}\end{gathered}$

$\begin{gathered}\qquad \; \dashrightarrow\; \; \sf {Area_{(Circle)}=4\times \: 1386}\end{gathered}$

$\qquad \;{\dashrightarrow\; \;{\underline{\boxed{ \pmb{ \pmb{\pmb{\sf{Area_{(Circle)} = {5584cm}^{2} }}}}} \;{\red{\pmb{\bigstar}}}}}}$

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$\therefore$ The Area of Circle is 5584cm² .

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