Question

what does 6π inches mean

Answer 1

Well, that is the Pi symbol. So maybe pi multiplied by 6.

Answer 2

Perhaps they meant for the number to stay as exact as possible, so they wrote Pi, instead of the number.

I would say it would be equal to 18.84955592.... inches

Answer 3

6π inches mean, 6 multiplied by pi . and pi = 3.14159

so we get 18.8495..