The Móhé Fanggài is a geometric solid in Chinese mathematics that was conceptualized by the ancient mathematician Liu Hui during his study of the volume of a sphere. This elegant structure consists of two identical right circular cylinders of equal radius intersecting perpendicularly on a common plane such that their bases form a square-like configuration when viewed along the intersection axis, hence the name “Móhé Fanggài,” which can be translated as “joined square lids.”