SOLUTION: If my paper says to find the circumference of a circle whose raius is 4 inches, what do I do? I understand that you multiply the 4 by 2, but it also says to use 3.14 for pi. I do n

Algebra ->  Circles -> SOLUTION: If my paper says to find the circumference of a circle whose raius is 4 inches, what do I do? I understand that you multiply the 4 by 2, but it also says to use 3.14 for pi. I do n      Log On


   



Question 576486: If my paper says to find the circumference of a circle whose raius is 4 inches, what do I do? I understand that you multiply the 4 by 2, but it also says to use 3.14 for pi. I do not understand what 3.14 has to do with the problem when it wants me to show the solution/formula. This is what I did: 2×4 = 8 inches
Found 2 solutions by jim_thompson5910, solver91311:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Circumference: C = 2pi*r

C = 2pi*r

C = 2(3.14)(4)

C = 25.12


So the circumference is roughly 25.12 inches.

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


, a trancendental irrational number approximated by the rational number 3.14, is the ratio between the circumference and the diameter of any circle. The diameter of a circle is 2 times the radius, so by multiplying the radius of 4 by 2, you managed to discover the measure of the diameter, which is, indeed, 8. But in order to determine an approximate value of the circumference of the circle, that is, the distance around the circle (as opposed to the distance straight across through the center which is the diameter).

So what you have to do is multiply 8 times 3.14 to get a two-decimal place accurate approximation of the measure of the circumference.

By the way, the only way to represent the circumference exactly is to write

John

My calculator said it, I believe it, that settles it
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