An outside circular ring has a circumference of 100 cm. What is the circumference of an inner ring which is 5 cm shorter in radius? Both circles have the same center.
one circle inside another sharing the same center

20.0 cm

31.8 cm

56.8 cm

68.6 cm An outside circular ring has a circumference of 100 cm. What is the circumference of an inner ring which is 5 cm shorter in radius? Both circles have the same center.
one circle inside another sharing the same center

20.0 cm

31.8 cm

56.8 cm

68.6 cm @Mathematics

Question

An outside circular ring has a circumference of 100 cm. What is the circumference of an inner ring which is 5 cm shorter in radius? Both circles have the same center.
one circle inside another sharing the same center

20.0 cm

31.8 cm

56.8 cm

68.6 cm  An outside circular ring has a circumference of 100 cm. What is the circumference of an inner ring which is 5 cm shorter in radius? Both circles have the same center.
one circle inside another sharing the same center

20.0 cm

31.8 cm

56.8 cm

68.6 cm  @Mathematics

hoblos · Answer

is there any formula for circumference?

anonymous · Answer

if there is i dont kno it haha :/ sad...but true

hoblos · Answer

lol

anonymous · Answer

68.6 cm

anonymous · Answer

i can always count on dear shabeer to save tha day haha

hoblos · Answer

abdul shabeer is there any formula??

anonymous · Answer

Are the options rounded off ?
I got the answer as 68.57142 still more

anonymous · Answer

Circumference of circle = $$2*\Pi*r$$

anonymous · Answer

68.6cm.....