Question

rose mila is a graduate from clcs trying to solve a question which states, "A circle has an area of 28.26 cm^2. what will be the circumference if the circle?.

Answer 1

Thanks for asking the question!

ANSWER::

Area of circle(A) = π r² = 28.26 cm²

28.26 = π r²

√(28.6 / π ) = r

Now , Circumference of circle (C) = 2 π r

Substitute value of r

C = 2 π √(28.6 / π )

C = 2 √( π x 28.6)

C = 2 √( 3.14 x 28.6)

C = 2 √89.80

C = 2 x 9.47

C = 18.94 cm

Hope it helps!

Answer 2

Let, the radius of the circle be r.

$\underline{\bold{Given}}$

Here, area of circle is given so first of all we have to find out the radius.

$Area \: of \: the \: circle = 28.26 \: {cm}^{2} \\ \\ \: \: \: \: \: \: \: \: \: \pi {r}^{2} = 28.26 \: {cm}^{2} \\ \\ \: \: \: \: \: \frac{22}{7} {r}^{2} = 28.26 \: {cm}^{2} \\ \\ \: \: \: \: \: \: \: \: {r}^{2} = 28.26 \times \frac{7}{22} {cm}^{2} \\ \\ \: \: \: \: \: \: \: {r}^{2} = 9 {cm}^{2} \\ \\ \: \: \: \: \: \: \: r = \sqrt{9 \: {cm}^{2} } \\ \\ \: \: \: \: \: \: \: r = 3 \: cm$
So, the radius of the circle is 2 centimetre.

Now, using the formula of circumference we can find out the circumference form it's radius.

$\underline{\bold{ Circumference \: of \: circle \:}}$

$= 2 \: \pi \: r \\ \\ = 2 \times \frac{22}{7} \times 3 \\ \\ = \frac{132}{7} \\ \\ = 18.85cm$

So, the circumference of the circle is 18.85cm.