# 8 Apothem ...from old math term notes

Apothem The distance from the center of a regular polygon to the sides, the apothem, comes from the Greek term "to set off", as in to set apart. The word is frequently pronounced "a poth' em' with the accent on the second syllable, but the traditional, and dictionary pronunciation is with the accent on the first syllable, "ap' e thum" as in apogee, which shares the ap root, and means off from the Earth (gee from geos). Apothem appears to be of modern origin despite its ancient name, and seems to have first appeared in English in the mid 1800's

According to Jeff Miller's website on the first use of math terms:

APOTHEM is found in 1828 in Elements of Geometry and Trigonometry (1832) by David Brewster (a translation of Legendre): The radius OT of the inscribed circle is nothing else than the perpendicular let fall from the centre on one of the sides: it is sometimes named the apothem of the polygon.