Question

If the perimeter of a circle is 40cm .what is radius

Answer 1

Circumference =  *2r, where r represents the radius of th circle.

We'll replace the known values within the formula of circumference:

40 =  π*2r

r = 40/2π

r = 20/π

We'll take  π= 3.14

r = 20/3.14

r = 6.36 cm

The requested radius of the circle is of 6.36 cm.

Answer 2

$perimeter \: of \: circle \: = 2\pi r$

$40 = 2\pi r \\ \pi r = 20 \\ r = \frac{20}{\pi}$

$\pi = \frac{22}{7}$

$r = \frac{20 \times 7}{22}$

r=70/11

r=6.3 cm