Question

1.8
Q3. The area of a semicircular region is 308 cm2 . Find its perimeter.​

Answer 1

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The area of a semicircular region is 308 cm² . Find its perimeter.

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☯︎ Area of semicircular region = 308cm²

➙ $\frac{1}{2}$πr² = 308

➙ πr² = 616

➙ $\frac{22}{7}$ × r² = 616

➙ r² = $\frac{616×7}{22}$

➙ r² = 28 × 7

➙ r² = 196

➙ r = $\sqrt{196}$

$\huge{\red{\boxed{\green{\tt{14\:cm}}}}}$

Now,

Perimeter of semicircular region = πr

➙ $\frac{22}{7}$ × 14

➙ 22 × 2

$\huge{\purple{\boxed{\orange{\tt{44\:cm}}}}}$