The demonstration of how to derive the circle area formula was the clincher, especially because of how similar that derivation is to other famous classical phys

The demonstration of how to derive the circle area formula was the clincher, especially because of how similar that derivation is to other famous classical physics formulae. That was the only example I could previously conceive for why pi was still useful, but now I see that the factor of 1/2 in A = (1/2)τr² shouldn't be avoided.