Call me a mathematical extremist but I think pi should equal 6.28... and tau, which looks like half of pi, should equal 3.14...

In 1897, the Indiana General Assembly attempted to legislate a new value for pi, proposing it be defined as 3.2, which was based on a flawed mathematical proof. This bill, known as the Indiana pi bill, never became law due to its incorrect assertions and the prior proof that squaring the circle is impossible: https://en.wikipedia.org/wiki/Indiana_pi_bill