Menelaus of Alexandria

Menelaus of Alexandria (/ˌmɛnɪˈleɪəs/; Ancient Greek: Μενέλαος ὁ Ἀλεξανδρεύς, Menelaos ho Alexandreus; c. 70 – 140 CE) was a Greek[1] mathematician and astronomer, the first to recognize geodesics on a curved surface as natural analogs of straight lines.

Although very little is known about Menelaus's life, it is supposed that he lived in Rome, where he probably moved after having spent his youth in Alexandria.

Ptolemy (2nd century CE) also mentions, in his work Almagest (VII.3), two astronomical observations made by Menelaus in Rome in January of the year 98.

Ptolemy used these observations to confirm precession of the equinoxes, a phenomenon that had been discovered by Hipparchus in the 2nd century BCE.

Composed of three books, it deals with the geometry of the sphere and its application in astronomical measurements and calculations.