Question

If radius of a circle is 21 cm. find the area and circumference of the circle. ​

Answer 1

$\huge\tt{\bold{\purple{\underbrace{\red{\mathfrak{ɾҽզմíɾҽժ⠀αղsաҽɾ♡༄}}}}}}$

$\huge{\fbox{\pink{Given:-}}}$

Radius of the circle:- 21 cm.

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$\huge{\fbox{\pink{To find:-}}}$

• Area of the circle.
• Circumference of the circle.

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$\huge{\fbox{\pink{Solution:-}}}$

Area of the given circle:-

$area \: of \: the \: circle = \pi {r}^{2} \\ \implies area \: of \: the \: circle =\pi {(21)}^{2} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \implies area \: of \: the \: circle = \frac{22}{7} \times 21 \times 21 \\ \implies area \: of \: the \: circle = \: {1385.44 cm}^{2} \: \: \: \: \: \: \: \: \: \: \:$

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Circumference of the circle:-

$circumference \: of \: a \: circle = 2\pi r \\ \implies \: circumference \: of \: a \: circle = 2\pi \times 21 \: \: \: \: \: \: \: \: \\ \implies \: circumference \: of \: a \: circle =2 \times \frac{22}{7} \times 21 \\ \implies \: circumference \: of \: a \: circle =132 \: cm \: \: \: \: \: \: \: \: \: \: \: \: \:$

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$\huge{\fbox{\pink{Formulae Used:-}}}$

$\star \: area \: of \: a \: circle \: = \: \pi \: {r}^{2} \\ \\ \star \: circumference \: of \: a \: circle = 2\pi r$

Answer 2

$\huge{\fbox{\pink{Answer:-}}}$

• Area = 1385.44 cm.^2
• Circumference = 132 cm.