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When three or more lines intersect at one point, then they are considered concurrent.The four points of concurrence in triangles are the circumcenter, incenter, centroid, and orthocenter.
Circumcenter, incenter, orthocenter and centroid.
In geometry, two or more lines are said to be concurrent if they intersect at a single point. If they do not intersect at the single point they are non concurrent.
Six triangles
4 points define a plane.
parallel
No, 2 points define a line, 3 points define a plane.
64 triangles
No, two points define a line. It takes three points to define a plane.
There are two ways to think of this question, if the triangles don't have to intersect then the answer is zero. If the triangles have to intersect, then the minimum number of points is one, if the triangles meat at vertex to edge or vertex to vertex.
The least number of obtuse triangles, if all possible triangles are drawn for n points in a plane, is zero. If all the n points lie in a straight line, no triangles are possible and so no obtuse triangles are able to be drawn; thus for any number n, there is a possibility that no obtuse triangles can be drawn, so the least possible number of obtuse triangles drawn is zero.
A point of concurrency is a place where three or more, but at least three lines, rays, segments or planes intersect in one spot. If they do, then those lines are considered concurrent, or the the rays are considered concurrent.