Question

(Maths)7th the circumference of a circle is 31.4cm find the radius and the area of the circle?(take π=3.14)

Answer 1

Answer:

Step-by-step explanation:

2πr=31.4

2×3.14×r=31.4

r=5cm

Area of circle=πr²

                      =3.14(5²)

                      =3.14(25)

                      =78.5cm²

Answer 2

Answer:

Radius is 5cm

Area of circle is 78.5 cm sq

Step-by-step explanation:

Given that

Circumference of circle is 31.4cm

π is 3.14

To find

Radius of circle

and

Area of circle

Solution

Let

c as circumference of circle

r as radius of circle

a as area of circle

As we know that

$c = 2\pi \times r$

$r = \frac{31.4}{2 \times 3.14}$

by solving we get

$r = 5$

hence Radius of circle is 5cm.

Now as we know that

$a = \pi \times {r}^{2}$

$a = \pi \times {5}^{2}$

$a = 3.14 \times 25$

by multiplication we get

$a = 78.5 {cm}^{2}$

hence area of circle is 78.5cm sq.