EntityQ3298255· pop 7· linked from 12 articlesSoddy's hexletSign in to savechain of 6 spheres tangent to 3 given spheresConnectionsgeometryEntityInternational Standard Book NumberEntitysphereEntityWayback MachineEntityKanagawa PrefectureEntitydigital object identifierEntityellipseEntitytheoremEntityplaneEntityparabolaEntityFrederick SoddyEntityhyperbolaEntitytorusEntityNatureEntitytangentEntityGaspard MongeEntityif and only ifEntityScientific AmericanEntityMathWorldEntitymathematical notationEntityCategoriesEuclidean solid geometryInversive geometryTheorems in geometry