In geometry, a Steinmetz solid is the solid body obtained as the intersection of two or three cylinders of equal radius at right angles. Each of the curves of the intersection of two cylinders is an ellipse.
The intersection of two cylinders is called a bicylinder. Topologically, it is equivalent to a square hosohedron. The intersection of three cylinders is called a tricylinder. A bisected bicylinder is called a vault,[1] and a cloister vault in architecture has this shape.
Steinmetz solids are named after mathematician Charles Proteus Steinmetz,[2] who solved the problem of determining the volume of the intersection. However, the same problem had been solved earlier, by Archimedes in the ancient Greek world,[3][4] Zu Chongzhi in ancient China,[5] and Piero della Francesca in the early Italian Renaissance.[3] They appear prominently in the sculptures of Frank Smullin.
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