A circle has a radius of 21m. Whats its circumference?

C = 2πr

C = 2π(21m)

C = 131.94 m or 132 m answer//

when r is the radius of a circle, then

circumference = 2 * pi * r

here,

circumference= 2 * (22/7) * 21 m = 132 m

Circumference of circle = 2πr

r=21m

π=3.14

∴ Circumference= 2xπx21

= 2*3.1*21

=131.88m

Circumference of a circle = 2 pi r 2(3.14 )=6.28*21

6.28

21

=====

6 28

125 60

---------

13188 approx. 131.88m or 42 oi m

Circumference = 2 * pi * radius

Pi = about 3.14

= 2 * 3.14 * 21

Answer: 131.88

Use the formula: C=πd

Diameter= 21 x 2 = 42m

C= π x 42

C=131.9468914512

C= 131.95m

Hope this helped :-)

Take the radius, and multiply by 2 times 3.141593. That's the formula to use for any radius.

131.88m :)