Even if you don't understand how the Hebrews represented their numbers or know the accuracy of their tools, it's still easy to see why it would be fallacious to try to "disprove the Bible" using 1 Kings 7:23.
The verse in question says (according to the Everything King James Bible):
7:23 And he made a molten sea, ten cubits from the one brim to the other: it was round all about, and his height was five cubits: and a line of thirty cubits did compass it round about.
Each of those measurements is only represented with one
significant digit. Thus any calculations made with those figures would properly be constrained to one significant digit as well. And
Pi to one significant digit equals 3.
This actually makes a lot of sense: When I am measuring something with a ruler, I usually round off to the nearest unit. This would be particularly true if I were measuring a sea of molten metal.