👉 Pentaspherical is a mathematical concept in spherical geometry that refers to a shape or object which has four equal sides and twelve equal angles. These angles are called "pentagons" because they consist of five right-angled triangles formed by connecting the vertices of the polygon. The term "penta-" comes from the Greek word "pentos," meaning "five." So, in the context of spherical geometry, a pentaspherical shape is a four-sided shape that has twelve equal angles.