词条 | Menelaus of Alexandria |
释义 | Menelaus of Alexandria Greek mathematician flourished 1st century AD, Alexandria and Rome Greek mathematician and astronomer who first conceived and defined a spherical triangle (a triangle formed by three arcs of great circles on the surface of a sphere). ![]() ![]() Although Book III contains the first-known extension of Menelaus's theorem for spherical triangles, it is quite possible that the theorem was already known and Menelaus simply transmitted it to later generations. In the form stated in Book III, the theorem became of fundamental importance in spherical trigonometry and astronomy, and the theorem has since been known by his name. Other works are attributed to him, including one on setting times of the signs of the zodiac, one (in six books) on chords in a circle, and one (in three books) on elements of geometry, but his only extant work is Sphaerica. Menelaus was not just a theoretical astronomer, as attested by the Almagest where Ptolemy (c. AD 100–170) reports Menelaus's observations of lunar occultations of stars. |
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