There are none.
base of a triangle
There are no geometry terms that start with the letter J. Geometry deals with the spatial relationships of objects.
Between and base are geometry terms. They begin with the letter b.Some others are:BreadthBisectorBearingsBoxBlockBorderlineBridgeB squared as in Pythagoras' theoremBreakBottomBiggerBilateral
circle cylinder circumference cone
Join, joint, justify
Undecagon-An earlier term for an 11 sided pollygon
Trapezoid and triangle are geometry terms. They begin with T.