Question

The area of a circle is 78 1/2 sq cm. Find its circumference.

Note:
$area \: of \: a \: circle \: = \pi {r}^{2}$
​

Answer 1

Answer:

Area of circle = 78 1/2 sq cm

πr^2. = 157/2

22/7 × r^2 = 157/2

r^2. = (157×7)/44

r^2. = 24.977 (approx.)

r^2. = 25 (approx. and round off )

r =. √25

r. = 5 cm

Now ,

Circumference of circle = 2πr

= 2 × 22/7 × 5

= 220/7 cm

= 31 3/7 cm Ans...

Answer 2

Answer:

31.31

Step-by-step explanation:

Circle

Solve for circumference

C≈31.31

A Area 78

Using the formulas

A=πr2

C=2πr

Solving forC

C=2πA=2·π·78≈31.30778