A noun used to describe a girl who one does not know, often as a substitute for her name. One, however, would not directly address a person as broher. Usually, this person is someone who the speaker does not care for or is ambiguous about.
When some math geeks celebrate their birthday by having each half of their cake cut into four pieces, with three of them each having an arc length equal to the radius of the cake.
Deduce that pi slices of pie leads to the fact that “2π radians = 360 degrees.”