|A) 20||B) 160|
|C) 164||D) 220|
For a triangle, we need 3 non-collinear points. So with 12 points (when all the 12 are such that any three non-collinear is. But among them 8 points are collinear.
If all these 8 points are different we get triangles as they are collinear.
In triangles, we do not get triangles
Therefore, The number of triangles we get = = 164