What are the diameter and radius of a circle with a circumference of 28π m?

A.
d = 28 m
r = 14 m

B.
d = 14 m
r = 28 m

C.
d = 14 m
r = 7 m

D.
d = 7 m
r = 14 m

Question

What are the diameter and radius of a circle with a circumference of 28π m?
 
 A.
d = 28 m 
r = 14 m
 
 B.
d = 14 m 
r = 28 m
 
 C.
d = 14 m 
r = 7 m
 
 D.
d = 7 m 
r = 14 m

jim_thompson5910 · Answer

The circumference of a circle is C = 2*pi*r 

In this case, C = 28pi (given)

jim_thompson5910 · Answer

plug that in to get

C = 2*pi*r 

28pi = 2*pi*r 

now solve for r and tell me what you get

anonymous · Answer

I think u would dive 28 into3 but then that does not work because u would then add up to 9.33333333

jim_thompson5910 · Answer

Here's how you solve for the radius r

28pi = 2*pi*r 

28pi/pi = 2*pi*r/pi  ... Divide both sides by pi.

28 = 2*r

28/2 = 2r/2 ... Divide both sides by 2.

14 = r

r = 14

jim_thompson5910 · Answer

To find the diameter d, you use the formula

d = 2*r

basically the diameter is twice as long as the radius