# simple(?) area of a circle question

• Jul 26th 2012, 11:39 AM
alanjm
simple(?) area of a circle question
Ok, so I have to give the answer in the correct amount of significant digits.

The diameter of a circle is 16.0m. Find the area.

I know how to work the answer out correctly, but I am unsure of how many significant digits I should use..

16.0m/2=8

pi(8^2) = area

so... do I use 3 significant digits (based on 16.0) or do I use 1 significant digit (based on 8)?
• Jul 26th 2012, 11:49 AM
ebaines
Re: simple(?) area of a circle question
You use 3 significant digits, because that's the data you were given. More formally the calculation is:

16.0m/2 = 8.00m
pi(8.00m)^2 = area
• Jul 26th 2012, 11:54 AM
alanjm
Re: simple(?) area of a circle question
Quote:

Originally Posted by ebaines
You use 3 significant digits, because that's the data you were given. More formally the calculation is:

16.0m/2 = 8.00m
pi(8.00m)^2 = area

Thank you! That's what I thought but wasn't sure! :)
• Aug 3rd 2012, 11:13 PM
manoj9585
Re: simple(?) area of a circle question
why are you so confused? as we know and work with this formula. In my opinion we should follow all given formulas of maths to got each results properly. You can choose free tutoring online for that purpose.