can someone help me with geometry?

Question

7. Given a circumference is 50 meters, what is the radius, EXACTLY?

Answer 1

C=2(pi)r, so the radius is C/2(pi)
Leave the pi in there - don't put it as a decimal. That's what they mean by "exactly"

Answer 2

the circumference can be found by pi multipy the diameter
if (pi)(dia) = 50
then 50 divide pi will give you the answer to the diameter.
since the diameter is two times as big as the radius, you divide the diameter by 2 and this gives you the radius :D

Answer 3

The formula for circumference in C=2πr. So...
50=2πr
25=πr
25/π = r

Answer 4

c=pi*d formula for circumference
50=pi*d substitute c for 50
---- ------
pi = pi divide both sides by pi

50/pi=d diameter

r=d/2 formula for radius

(50/pi)/2=d/2 divide both sides by 2

(50/pi)/2 = d/2


d/2 =r

(50/pi)/2=r Substitution

i think the answer would be (50/pi)/2= r since you need an exact answer. you would have to leave it as a formula since pi is neverending. if you could estimate, then you would just put in 3.14 for pi and get 7.96

Answer 5

c=2*PI*r so r=c/2*PI so, r=50/2*3.14 so r = 7.96