Question

find the area of a circle whose circumfence is 22cm​

Answer 1

Answer:

A≈38.52cm²

Let r be the radius of the circle.

Then, Circumference=22cm

⇒2πr=22

⇒2× 22/7 ×r=22

⇒r= 7/2 cm

∴ Area of the circle=πr2

= 22/7 × 7/2× 7/2cm2

=38.5cm

Answer 2

$Let \: radius \: of \: a \: circle (r) = a \:cm$

$Circumference \: of \: the \: circle = 22 \: cm$

$\implies 2 \pi r = 22$

$\implies 2\times \frac{22}{7} \times r = 22$

$\implies r = \frac{22\times 7 }{2 \times 22 }$

$\implies r = \frac{ 7 }{2 } \: ---(1)$

$Area \: of \: the \: circle = \pi r^{2}$

$= \frac{22}{7} \times \Big( \frac{ 7 }{2 }\Big)^{2}$

$= \frac{22}{7} \times \frac{ 7 }{2 }\times \frac{7}{2}$

$= 11 \times \frac{7}{2}$

$= \frac{77}{2}$

$= 38.5 \: cm^{2}$

Therefore.,

$\red{ Area \: of \: the \: circle}\green { = 38.5 \: cm^{2}}$

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