2
Two distinct (different) points are needed to determine a line.
Three non-collinear points do not determine a unique spherical triangle.
2
No. If the four points are coplanar, they determine only one plane!
A plane can be determined by three points, as long as the three points do not lie along a single line.
A series of 3 points will always determine a plane unless 2 or all 3 points are identical points (they have the same coordinates).If the idea is to have the three points determine oneplane, a unique plane, then three points will do that as long as none of them have the same spacial coordinates (have identical locations) or as long as the three points do not lie on a single line.If a straight line can be drawn through all three points, they will not form one unique plane either.
Three
In plane geometry, two points determines or defines one unique line.
8 collinear points determine 28 unique line segments
A series of 3 points will always determine a plane unless 2 or all 3 points are identical points (they have the same coordinates).If the idea is to have the three points determine oneplane, a unique plane, then three points will do that as long as none of them have the same spacial coordinates (have identical locations) or as long as the three points do not lie on a single line
It takes exactly 2 distinct points to uniquely define a line, i.e. for any two distinct points, there is a unique line containing them.
a plane is any plane surface it usually have 3 or 4 points * * * * * You need only three points provided they are not collinear. And most planes have infinitely many points although there are geometries with only a finite number of points.