Question

Find the radius of a circle whose circumference is 57.2cm

Answer 1

circumference of a circle= 2×pi×r
57.2cm= 2×22/7 × radius
57.2 cm ×7 = 44 × radius
400.4cm/44 = radius
radius= 9.1 cm

check:
2× pi×r
2×22/7×9.1
=57.2 cm^2


hope it helps...

Answer 2

Hi friend,

Circumference=57.2 cm
We find circumference using 2*pi*r forumula.
Radius=? let it be r
Radius=

57.2=2*22/7*r

572/10=2*22/7*r

572*7/10*2*22=r

r=9.1 cm

CHECK-:

Circumference=2*pi*r

= 2*22/*9.1

=57.2 cm

Hope it helped you..................