Question

Find the area of shaded portion​

Answer 1

$\large\underline{\sf{Solution-}}$

Let assume that

x represents the radius of semicircle having diameter 3.5 cm.

y represents the radius of semicircle having diameter 2.8 cm

r represents the radius of the semicircle having diameter 2.8 + 3.5 = 6.3 cm

So, it means radius of semicircles are

$\rm \: x = 1.75 \: cm$

$\rm \: y = 1.4 \: cm$

$\rm \: r = 3.15 \: cm$

Now, Required area of shaded region is

$\rm \: = \: 2 \times \bigg[\dfrac{1}{2} {\pi \: r}^{2} + \dfrac{1}{2} {\pi \: x}^{2} - \dfrac{1}{2} {\pi \: y}^{2} \bigg]$

$\rm \: = \: 2 \times \dfrac{\pi}{2} \times \bigg( {r}^{2} + {x}^{2} - {y}^{2} \bigg)$

$\rm \: = \: \pi \bigg( {3.15}^{2} + {1.75}^{2} - {1.4}^{2} \bigg)$

$\rm \: = \: \dfrac{22}{7} \times \bigg(9.9225 + 3.0625 - 1.96 \bigg)$

$\rm \: = \: \dfrac{22}{7} \times 11.025$

$\rm \: = \: 22 \times 1.575$

$\rm \: = \: 34.65 \: {cm}^{2}$

Hence,

$\color{blue}\rm \:Required \: area \: of \: shaded \: region \: is = \: 34.65 \: {cm}^{2}$

$\rule{190pt}{2pt}$

Additional Information :-

$\begin{gathered}\begin{gathered}\boxed{\begin {array}{cc}\\ \dag\quad \Large\underline{\bf Formulas\:of\:Areas:-}\\ \\ \star\sf Square=(side)^2\\ \\ \star\sf Rectangle=Length\times Breadth \\\\ \star\sf Triangle=\dfrac{1}{2}\times Base\times Height \\\\ \star \sf Scalene\triangle=\sqrt {s (s-a)(s-b)(s-c)}\\ \\ \star \sf Rhombus =\dfrac {1}{2}\times d_1\times d_2 \\\\ \star\sf Rhombus =\:\dfrac {1}{2}d\sqrt {4a^2-d^2}\\ \\ \star\sf Parallelogram =Base\times Height\\\\ \star\sf Trapezium =\dfrac {1}{2}(a+b)\times Height \\ \\ \star\sf Equilateral\:Triangle=\dfrac {\sqrt{3}}{4}(side)^2\end {array}}\end{gathered}\end{gathered}$

Answer 2

$<marquee>illilli Your required answer is in the attachment Illilli</ marquee>$

$\red{ Formula \: used} \\ \\ = \green{ \frac{22}{7} \times r {}^{2} } \\ \\ \blue{Brainliest \: Please \: }$