# Thread: simple(?) area of a circle question

1. ## 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)?

2. ## 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

3. ## Re: simple(?) area of a circle question

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!

4. ## 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.