How to use the PI constant in Dart

As an alternative to the accepted answer, you can keep importing without a prefix, and reference pi as just pi:

import "dart:math" show pi;
main() {
  print(pi / 12);
}

This works just as well as prefixing. It's a matter of taste which one you prefer.

First import 'dart:math'; then use pi/12.0 instead of math.PI/12.0 it should work fine.

you should import 'dart:math' as math; instead of just import 'dart:math';

because when you use the as keyword you provide the imported library a name so you can reference it anywhere in your file