gon-, gonio-, -gon, -gonal, -gonally, -gony

(Greek: corner, bend, angle)

agonic (adjective)
Not forming an angle; having no angle: "The line indicating the perimeter of a circle is an agonic line."
decagon
diagon
diagonal
1. Extending between nonadjacent angles in a polygon figure.
2. Having slanting marks, lines, etc.
dodecagon
enneagon
goniometer
goniometry
hendecagonal
heptagon
hexagon
isogonic
Having , or pertaining to, equal angles.
nonagon, nonagonal; enneagon
A polygon having nine angles and nine sides.
octagon
orthogonal
1. Having or determined by right angles; perpendicular.
2. An area of a computer display in which units of distance are the same horizontally and vertically so that there is no distortion.