The Bible does not say or imply that pi is three.

2 Chronicles 4

2. Also he made a molten sea of ten cubits from brim to brim, round in compass, and five cubits the height thereof; and a line of thirty cubits did compass it round about.

5. And the thickness of it was an handbreadth, and the brim of it like the work of the brim of a cup, with flowers of lilies; and it received and held three thousand baths.

The diameter was measured from brim to brim, not from edge to edge, so the circumference would be slightly longer at the brim than the circumference of the actual sea. All you would need is to have each brim being about 4 inches wide (which is quite reasonable for a sea of 10 cubits in diameter) and the math would work out perfectly. 30 cubits divided by pi is approximately 9.55 cubits, so the total width of the two brims added together would be about .45 cubits. .45 cubits would be approximately 8 inches (with a cubit being 18 inches). So that would make the width of each brim about 4 inches. So if you subtract the widths of the two brims, you have the sea itself being about 9.55 cubits in diameter, which, multiplied by pi would give you 30 cubits.

The fact that the sea was measured from brim to brim is quite often overlooked, which is what makes the math look wrong. But when they are added to the equation (or rather, subtracted from it), it makes the math exactly right.