Question

Find the area and cirum a circle of no radis 21cm.

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Answer 1

Given, radius r=21cm and π= 22/7

Then,

Area of the circle = πr square units

22/7 ×21×21

=22×3×21

=1386cm square

Hence area is 1386 cm square

Let's find circum now ,

C=2πr=2·π·21≈131.94689

Answer 2

Given:

The radius of the circle is 21cm

To find:

Area and Circumference

Solution:

We know,

  Area of the circle = $\pi r^{2}$

 So,

  Area = 3.14 * 21 * 21 $cm^{2}$

⇒  Area = 1384.74 $cm^{2}$

We know,

 Circumference = 2 $\pi$r

So,

C = 2 * 3.14 * 21 cm

⇒  C = 131.88 cm

Hence, Area and Circumference are 1384.74 $cm^{2}$ and 131.88 cm.