Question

The circumference of circle is 31.4cm. find the radius and the area of the circle ?​

Answer 1

Answer:

r=5cm

Step-by-step explanation:

Using the formula

C=2πr

Solving forr

r=C

2π=31.4

2·π≈4.99747cm

Answer 2

Given -

Circumference of circle is 31.4 cm

To find -

The area of circle

Solution -

As we know that,

Circumference of circle = $2 \times \pi \times r$

Put the given values in these formula we get

$31.4 = 2\pi \times r$

$\frac{31.4}{2\pi} = r$

$\frac{15.7}{\pi} = r$

The value of π is 3.14 .

$\frac{15.7}{3.14} = r$

$r = 5$

So,

Radius (r) is 5 cm.

Area of circle = $\pi {r}^{2}$

Put the value of r we get

Area of circle = $\pi \times {5}^{2}$

Square means multiply the given values with itself twice.

Square of 5 is 25

Area of circle = $\pi \times 25$

The value of π is 3.14.

Area of circle = $3.14 \times 25$

Area of circle = $78.5$

Hence,

Area of circle is 78.5${cm}^{2}$ .