Question

The circumference of a circle is
314cm .Find the radius and the area of circle .​

Answer 1

Explanation:

As we know that circumference of the circle is given as-

Circumference =2πr

Given:-

Circumference of the circle =31.4cm

∴2πr=31.4

⇒2×3.14×r=31.4

⇒r=5cm

Now again as we know that the area of the circle is given as-

Area =πr

2

⇒ Area =3.14×(25)

2

=78.5cm

2

Hence the radius and area of the circle is 5cm amd 78.5cm

2

respectively.

Answer 2

Answer:

• Radius of circle is 49.9 cm (approx).
• Area of circle is 7825.74 cm² (approx).

Explanation:

Given :-

• Circumference of circle is 314 cm.

To find :-

• Radius of circle.
• Area of circle.

Solution :-

• Circumference of circle = 2πr

Where,

r is radius of circle.

π is 22/7 or 3.14 .

Put the values :

$\rightarrow$ 314 = 2πr

$\rightarrow$ 314 = 2 × 22/7 × r

$\rightarrow$ 314 = 44/7 × r

$\rightarrow$ 314 × 7 = 44 × r

$\rightarrow$ 2198 = 44 × r

$\rightarrow$ 2198/44 = r

$\rightarrow$ r = 49.9

Thus,

Radius of circle is 49.9 cm (approx).

Now,

We know,

• Area of circle = πr²

Put r in formula :

$\rightarrow$ 22/7 × (49.9)²

$\rightarrow$22/7 × 2490.01

$\rightarrow$ 54780.22/7

$\rightarrow$ 7825.74

Therefore,

• Area of circle is 7825.74 cm² (approx).