There are no geometry terms that start with the letter J. Geometry deals with the spatial relationships of objects.
Presumably at the birth of the Universe.
Geometry
eicosohedron
right.
Tangent.
Presumably at the birth of the Universe
altitude
Starting from around 3rd-4th grade, you start to learn really basic geometry. But around 8th or 9th grade, you actually start to learn more advanced geometry that uses theorems and postulates and proofs.
Since this sentence is lacking a predicate, it is virtually impossible to answer. "Geometry words that start with r" is a legitimate noun phrase, but is so incomplete that it cannot be answered.
300 bc by euclid a greek mathmatician.
Skew