IPA: /nɒnˈkɒlɪnə/
KK: /nɑnˈkɑlɪnər/
Not lying on the same straight line; referring to points that do not all fall on a single line.
The three points are noncollinear, forming a triangle instead of a straight line.
Noncollinear → It is formed from "non-" (meaning not) and "collinear" (from Latin "collineare", meaning to lie in the same straight line). The word "noncollinear" describes points that do not lie on the same straight line.
Think of 'not' ('non-') being used to describe points that do not lie 'in the same line' ('collinear'). This helps you remember that noncollinear means points that are not aligned in a straight line.