Question

find the circumference and area of a circle of radius 4.2cm

Answer 1

$<marquee>☺ Hi Dear ☺</marquee>$

here is your answer

Area of circle = π x r 2 
Area = 3.14 x (4.2) 2 
= 55.44 cm 2 

hope you got it
thank you

Answer 2

Here is the answer ..

Question) Find the circumference and area of a circle of radius 4.2cm.

Answer..

Given
Radius = 4.2 cm

To find
Circumference = ?
Area of circle = ?

Solution

Circumference of circle = 2πr
$= 2 \times \frac{22}{7} \times 4.2 \\ = 2 \times 22 \times 0.6 \\ = 44 \times 0.6 \\ = \textbf{26.4 \: cm}$
Hence , the circumference of the circle is 26.4 cm.

Area of circle =
$= \pi {r}^{2} \\ = \frac{22}{7} \times {4.2}^{2} \\ = \frac{22}{7} \times 4.2 \times 4.2$
$= {22}{} \times 4.2 \times 0.6 \\ = 22 \times 2.52 \\ = 55.44 \: cm {}^{2}$

Hence, area of circle is 55.44 sq. cm.


Hence,
Final answer..
Circumference of circle is 26.4 cm
Area of circle is 55.44 sq cm.