Question

Find the circumference and the area of the circles having radius take n=22/7
a. 14 dm
b. 2.1 m
c. 4.9 cm​

Answer 1

Step-by-step explanation:

Given that

a)Radius is 14cm

b)Radius is 2.1m

c)Radius is 4.9cm

To find

Area and Circumference of circle

Solution

Let c as circumference of circle

a as area of circle

As we know that

$circumference \: of \: circle = 2 \times \pi \times radius$

and

$area \: of \: circle = \pi \times {radius}^{2}$

Put

$\pi = 3.14$

Now for

a) Radius is 14cm

$circumference \: of \: circle = 2 \times 3.14 \times 14$

by multiplication we get

$circumference \: of \: circle = 87.96 cm$

$a = \pi \times {14}^{2}$

$a = 615.75 {cm}^{2}$

b)Radius is 2.1m

$c = 2 \times 3.14 \times 2.1$

$c = 13.19m$

now

$a = \pi \times {2.1}^{2}$

$a = 3.14 \times {2.1}^{2}$

$a = 13.85 {m}^{2}$

c)Radius is 4.9cm

$c = 2 \times 3.14 \times 4.9$

$c = 30.78cm$

$a = 3.14 \times {4.9}^{2}$

$a = 75.42 {cm}^{2}$