Question

The area of a circle is 49 cm2. Find the circumference of the circle.

Answer 1

Answer:

C = 14 sqrt(pi)

Step-by-step explanation:

The formula for area of a circle is

A = pi r^2

49 = pi r^2

Divide each side by pi

49/pi = r^2

Take the square root of each side

sqrt(49/pi) = sqrt(r^2)

sqrt(49/pi) = r

Now we need to find the circumference

C = pi * 2 *r

C = pi * 2 * sqrt(49/pi)

C = pi * 2 *7/sqrt(pi)

We need to get rid of the qrt(pi) in the denominator) so multiply by sqrt(pi)/sqrt(pi)

C = pi * 2 *7/sqrt(pi) * sqrt(pi)/sqrt(pi)

C 14 pi* sqrt(pi)/pi

The pi in the numerator and denominator cancel

C = 14 sqrt(pi)

Answer 2

~Hello There!~

The formula to find the area of a circle is:

$\pi r^{2}$

We already know this answer, so we write it as:

$\pi r^{2} =49$

We need to calculate the radius (r) from this so divide both sides by $\pi$

$r^{2} = 15.59718442$

Square root this to get r

r = 3.949327085

The formula for circumference is $\pi *d$

(d is the diameter )

Double the radius to get the diameter:

d = 7.89865417

Multiply this value by $\pi$ to get the answer

The circumference is 24.81435391

Hope This Helps You!

Good Luck :)

Have A Great Day ^_^

- Hannah ❤