Question: is pi proven to be irrational?
Answer: Proof that π is irrational. In the 1760s, Johann Heinrich Lambert proved that the number π (pi) is irrational: that is, it cannot be expressed as a fraction a/b, where a is an integer and b is a non-zero integer. ... In 1882, Ferdinand von Lindemann proved that π is not just irrational, but transcendental as well.