Question

what is the area of semicircle whose diameter is 20 CM​

Answer 1

$\color{darkblue}\underline{\underline{\sf Given-}}$

• Diameter of semicircle (d) = 20cm

$\underline{\underline{\sf Radius \: of \: semicircle-}}$

$\implies{\sf R =\dfrac{d}{2}}$

$\implies{\sf R =\dfrac{20}{2}}$

$\implies{\sf \orange{R = 10cm}}$

$\color{darkblue}\underline{\underline{\sf To \: Find-}}$

• Area of semicircle (A)

━━━━━━━━━━━━━━━━━━━━━━━━━━━

$\color{darkblue}\underline{\underline{\sf Formula\: Used-}}$

$\color{violet}\blacksquare\underline{\boxed{\sf Area \: of \: semicircle (A)=\dfrac{πr^2}{2}}}$

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

$\implies{\sf A =\dfrac{πr^2}{2}}$

$\implies{\sf A =\dfrac{3.14×(10)^2}{2}}$

$\implies{\sf A =\dfrac{314}{2}}$

$\color{red}\implies{\sf A = 157cm^2 }$

$\color{darkblue}\underline{\underline{\sf Answer-}}$

Area of semicircle is $\color{red}{\sf 157cm^2}$.

Answer 2

✬ Area = 157 cm² ✬

Step-by-step explanation:

Given:

• Diameter of the Semicircle is 20 cm

To Find:

• What is measure of area of Semicircle?

Solution: First we have to find the radius of Semicircle.

$= > Radius = \frac{Diameter}{2} \\ \\ = > Radius = \frac{20 \: cm}{2} = 10 \: cm$

• Formula for finding area of Semicircle is •

★ Area of Semicircle = πr²/2 ★

• Take π = 3.14

$\implies \frac{\pi \: r ^{2} }{2} \\ \\ \implies \frac{3.14 \times (10 ^{2} )}{2} \\ \\ \implies \frac{3.14 \times 10 \times 10}{2} \\ \\ \implies \frac{314 \times 100}{100 \times 2} \\ \\ \implies \frac{314}{2} \\ \\ \implies 157 \: cm ^{2}$

Hence, The area of semi circle is 157 cm²