(Ὑψικλῆς; Hypsiklês). Hellenistic mathematician and astronomer. From the introduction to book 14 of Euclid's ‘Elements’ written by him, it follows that H. lived in Alexandria around 175 BC.
It is attested by MSS that he composed what later was added as book 14 to the ‘Elements’ of Euclides [3] (ed. [1]). Like bk. 13 it deals with the inscribing of regular bodies into a sphere and was thought of as an explanation to a lost work of Apollonius [13] about dodecahedra and icosahedra. H. shows that the planes that form an icosahedron and dodecahedron inscribed…