Why is it difficult to measure circumference accurately? answers?

One of either the circumference or distance across is not rational. If you have a bit of string precisely 1 inch long and you make it into an idealize circle, the distance across of that circle will be an irrational value. You could try to measure it, however regardless of how precisely you measured it, it would in any case not be very sufficiently precise. So, you can never know precisely what the diameter is just by measuring.

What's more, on the off chance that you took that string and made a width with it, the circumference would be irrational and you could never have the capacity to measure the circumference precisely enough. Whatever you quantified would be close however not correct.