I've been on this question for an hour and I really need help! So here's the problem:
I need to find the circumference of a circle with a radius of 38.4
The way the book shows how to find the circumference witht he radius is to do: 2 times 22 over 7(pi) times the radius.
I've been trying to do it this way but I don't know how to work it.
Could you please step by step show me how to do this and please include the answer? Thanks so much!
2006-12-11 12:15:45 · 10 answers · asked by allyjax_1 1 in Education & Reference ➔ Homework Help
I dont know the formula. I already typed the wya the book says to do it; thats the part I need help with.
2006-12-11 12:19:15 · update #1
Circumference of circle = 2*pi*radius
Since you are given the radius, plug into the equation. Also, remember that pi = 3.14:
Circumference = 2*(3.14)*(38.4) = 241.15
The way the book writes the formula is:
2*(22/7)*radius because 22/7 is approximately 3.14. Either way, just plug in the given radius and you will get the answer
--------
Hope this helps
2006-12-11 12:18:01 · answer #1 · answered by JSAM 5 · 0⤊ 1⤋
The diameter of a circle is the gap around the widest area of the circle. that's 2 situations the radius, that's the gap from the middle of the circle to the exterior. The circumference is the gap around the circle. The formulation for the circumference of a circle is two X pi X r. on the grounds that 2 X r = the diameter besides, the circumference of a circle is the diameter situations pi. Pi = 3 a million/7
2016-12-18 11:42:54 · answer #2 · answered by ? 4 · 0⤊ 0⤋
circumference is equal to Pi times the diameter.
Circumference of Circle = PI x diameter = 2 PI x radius
The formula you gave just about right. 22/7 is an approximation of pi.
2006-12-11 12:24:35 · answer #3 · answered by Jay 1 · 0⤊ 0⤋
The formula for finding the circumference of a circle (as you said) is 2*pi*radius (two times pi times radius).
So your problem:
radius = 38.4
2*pi*38.4= circumference
circumference = 241.3
2006-12-11 12:22:26 · answer #4 · answered by Josh 3 · 0⤊ 0⤋
ok first
double the radius which is 38.4 which is 76.8
then u times that by 3.14
i got 241.152
* times by 2 because the radius is half of the diameter
then u have the diameter times 3.14
it is easy just double the radius and multiply by 3.14 and if u r given the diameter just multiply by 3.14
hope i helped
2006-12-11 12:20:19 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Pi is the number of times the diameters fits into the cicumference.
The diameter is two times pi.
So all you have to do is to multiply the radious by 2 to obtain the diameter.
And then you multiply the diameter by Pi.
The way shown in your book is also correct:
You take pi and multiply by 2. That number you multiply by the radious and that is it.
2006-12-11 12:38:32 · answer #6 · answered by mfacio 3 · 0⤊ 0⤋
Circumference formula is C=d x pi
to get distance formula is d=2r
pi=3.14
take your radius of 38.4 multiplied by 2=76.8
C=(76.8)(3.14)=241.152
2006-12-11 12:23:34 · answer #7 · answered by slu70 1 · 0⤊ 0⤋
bumble bumble little bee
circumference equals pi d!
c=pi*diameter
if the radius is 38.4, the diameter is 76.8 (d=r*2; 38.4*2=76.8)
if they ask for the EXACT ANSWER then say 76.8pi. if they ask for a rounded answer, take pi (3.1415926535....) times 76.8; and round to the appropriate place
2006-12-11 12:25:39 · answer #8 · answered by Spearfish 5 · 0⤊ 0⤋
you multiply pi times the radius square pi being 3.1410 so you just square the radi and multiply it times 3.1410 i hope i helped you alyjax
2006-12-11 12:26:30 · answer #9 · answered by roy40372 6 · 0⤊ 0⤋
The formula is 2rπ. So, the question is (38.4)(2)(π), or 38.4*2*π
(π=3.14, 22/7, or just plain π)
2006-12-11 12:31:17 · answer #10 · answered by fiskeryatigo 1 · 0⤊ 0⤋