three dimensions, three-dimensional

triangular prism

three years; the third year / (education) the third school year / (figuratively) a long period of time, several years

three years; triennial / three years old

three years of age, three years old

excuse me; may I come in?

(physics) critical Reynolds number

Numbers

decimal point, radix point

A numerologist or arithmancer; practitioner of numerology or arithmancy.