spherical trigonometry

Objects more massive than a certain amount are more spherical than not, while punier specimens are lumpy and irregular.

And, oh, occasionally, the golden snitch—a flying spherical ball—will flutter into the proceedings, creating chaos.

Take a case in Trigonometry—a Complement is what remains after subtracting an angle from one right-angle.

When it is new, and also when in its waning stages it is visible in the daytime, the spherical form is very apparent.