A circular area having a radius $20 c m$ is divided into $2$ equal parts by a concentric circle of radius $r$ , then find the value of $r$ ?

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Solution

Given that:
$R = 20 c m$
Area of circle $= π R^{2} = π 20^{2} = 400 π$
Let radius is $r$ , when the circle is divided in to two parts then
Area of such circle $= π r^{2} \Rightarrow \frac{π 20^{2}}{2} = 200 π$
$r = 10 \sqrt{2} c m .$

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A circular area having a radius 20cm is divided into 2 equal parts by a concentric circle of radius r, then find the value of r?

Given that:R=20 cmArea of circle =πR2=π202=400πLet radius is r, when the circle is divided in to two parts thenArea of such circle =πr2⇒π2022=200πr=10√2 cm.

A circular area having a radius $20 c m$ is divided into $2$ equal parts by a concentric circle of radius $r$ , then find the value of $r$ ?

Given that:
$R = 20 c m$
Area of circle $= π R^{2} = π 20^{2} = 400 π$
Let radius is $r$ , when the circle is divided in to two parts then
Area of such circle $= π r^{2} \Rightarrow \frac{π 20^{2}}{2} = 200 π$
$r = 10 \sqrt{2} c m .$