I know one is X-Axis
x axsis
x-axis maybe?
X-axis and x-intercept start with x.
Geometric words that start with "x" include "x-axis," which refers to the horizontal axis in a Cartesian coordinate system, and "x-coordinate," indicating the horizontal position of a point. Additionally, "x-intercept" is the point where a graph intersects the x-axis. These terms are commonly used in mathematics and geometry.
Tangent.
Geometry
eicosohedron
right.
Whole Number
vector, vertex, vertical
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.
The horizontal x-axis on the Cartesian plane