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Changing a pi answer into a fraction answer without a calculator

How do you change a pi(3.14)answer into a fraction answer without a using calculator. A question came up on my exam this morning

Reply 1

NinJawad

I did the same question. its complicated, but uhh i think you get pi on both the top and the bottom of the fraction. this allows you to cancel them out and left with just numbers to simplify.

Reply 2

alexlopez4

simply, remember that pi in radians = 180 degrees.
therefore pi/4 in radians is 180/4 = 45 degrees
and pi/6 in radians is 180/6 = 30 degrees

Reply 3

poorform

You don't.

\displaystyle \pi

is an irrational number. There are some approximations like

\displaystyle \frac{22}{7}

and some more accurate ones but again they are only approximations to

\displaystyle \pi

. I'm guessing the question asked for something else so you will need to be more clear if you want an explanation. :biggrin:

(edited 8 years ago)

Reply 4

rxns_00

Original post by alexlopez4

simply, remember that pi in radians = 180 degrees.
therefore pi/4 in radians is 180/4 = 45 degrees
and pi/6 in radians is 180/6 = 30 degrees

They asked for a fraction, not degrees

Reply 5

davros

Original post by RonnieRJ

They asked for a fraction, not degrees

Do you remember exactly what the question was? The OP hasn't explained very clearly what's actually required :smile:

Reply 6

rayquaza17

I think we might need to see the full question here to be able to help properly.

Reply 7

President Snow

Well, I haven't a clue what the question is, but if you want to convert pi/3 into a fraction of a whole circle, simply consider (pi/3)/2pi = 1/6.

Similar techniques are useful for area and arc length calculations.