(illustration courtesy of pixabay.com)
Now, imagine that the goal of all of us, as described by the poets and mystics, is to attain oneness with the One (the point at the top of the triangle). One of the teachings concerning Twin Souls is that one of our final acts before attaining that Oneness is to balance the male and female sides of our personality. That's an inside job, achieving perfect equality of the two angles at the base of the triangle. Another teaching says that we must unite with our Twin Soul in order to achieve Unity. That is both external and internal. The figure of the triangle all points to this, see?
And if that completely blows your logical mind, that's OK, too.