minimum number of points a convex hull must have Quick question:
Say for example there are 10 colinear points. my question is does a convex hull have to be a convex polygon? or can it be a line as well according to the formal definition of the convex hull?
Thanks in advance.
The convex hull of 10 collinear points is the line segment between the two extreme points.
No, a convex hull does not have to be convex polygon. A convex hull can be a point, a line segment, a ray, a line, a convex polygon, a circular sector, a half plane, a cubic, etc. .
A definition in math, such as the definition of convex hull, is the strictest kind of definition. It means exactly what it says. No more, no less.