1) how do u find the circumference of a circle knowing the radius
2) how do u find the circumference of a circle knowing the diameter
* i need the formulas
2006-11-14 13:14:19 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
r=radius
d=diameter
1 C=2r(pi)
2 C=d(pi)
(Same thing because 2r=d)
2006-11-14 13:18:14 · answer #1 · answered by KnowhereMan 6 · 0⤊ 0⤋
The formula for the circumference of a circle with a known radius is C=2Ïr
And the formula for the circumference of a circle with a known diameter is
C=Ïd
2006-11-14 21:18:11 · answer #2 · answered by SomeGuy 6 · 0⤊ 0⤋
1) to find the circumference knowing the radius follow these directions: Radius X 2 Then you have the Diameter. Then you take your answer and multiply that by Pi (3.14) That is your answer. (R X 2 =D X PI = C)
2) take the diameter and multiply it by Pi (3.14)
(D X PI = C)
Hope I helped you!
2006-11-14 21:36:46 · answer #3 · answered by Shygurl 2 · 0⤊ 0⤋
1)multiply the radius by 2 then multiply by pi equals circumfrence
Rx2=Dx3.14=circumfrence
2)multiply the diameter by pi to get the circumfrence
Dx3.14=C
2006-11-14 21:25:55 · answer #4 · answered by Yo mamma...just kiddin 1 · 0⤊ 0⤋
c = pi(r^2)
r = (1/2)d
let c = circumference
let r = radius
let pi = 3.14
let d = diameter
2006-11-14 22:34:49 · answer #5 · answered by ikeman32 6 · 0⤊ 0⤋
c=2 pi r
c= pi d
2006-11-14 21:16:08 · answer #6 · answered by darcy_t2e 3 · 0⤊ 0⤋
well, 2r=d
and the circumference is
c=pi*d
and as for pi... usually stops at 3.14...
2006-11-14 21:17:02 · answer #7 · answered by J 5 · 0⤊ 0⤋