Question

1.Find the area of a circular ring whose outer and inner radii are 20cm and 15cm

respectively.​

Answer 1

Answer:

answer at down see in pic may it will helpful

Answer 2

Question :

Find the area of a circular ring whose outer and inner radii are 20cm and 15cm respectively.

To find :

Area of a circular ring =?

Given :

•Outer radii=20cm

• Inner radii =15cm

Solution :

$\boxed{\bf{\underline{Area \: of \: Ring=\: Area of \: outer \: circle -\: Area \: of \: inner \: circle}}}$

$\\ \implies \large \sf \: \pink \bigstar \: area \: of \: \: a \: outer \: circle = \pi( {20})^{2}$

$\\ \implies \large \sf \: area \: of \: a \: outer \: circle \: =400\pi$

$\\ \implies \large \sf \: area \: of \: outer \: circle = \frac{22}{7} \times 400$

$\\ \implies \large \sf \green \bigstar \: area \: of \: inner \: circle = \pi {(15)}^{2}$

$\\ \implies \large \sf \: area \: of \: inner \: circle = \pi(225)$

$\\ \large \implies \sf \: area \: of \: inner \: circle = \frac{22}{7} \times 225$

$\\ \therefore \large \sf \: area \: of \: ring = \frac{22}{7} \times 400 - \frac{22}{7} \times 225$

$\\ \therefore \large \sf \: area \: of \: ring \: = \frac{22}{7} (400 - 225)$

$\\ \implies \large \sf \: area \: of \: ring \: = \frac{22}{7} \times 175$

$\\ \implies \large \sf \: area \: of \: ring \: = \frac{22}{ \cancel7} \times \cancel{175} \: 25$

$\\ \implies \large \sf \: area \: of \: ring \: = 22 \times 25$

$\\ \implies \large \sf \: area \: of \: ring \: = 550 {cm}^{2}$

$\\ \large \red \heartsuit\boxed{ \underline{ \boxed{ \bf{area \: of \: ring \: = 550 {cm}^{2} }}}}$

▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬