How many triangles can be formed by joining 15 points on the plane, in which no line joining any three points?

How many triangle can be formed by joining 15 points on the plane, in which on line joining any three points?

How many triangles can be fromed by joining 15 points on the plane , in which no line joining any three points ?

How many triangles can be formed by joining 6 points lying on a circle ?

How many Triangles can be formed by joining 12 points, 4 of which are collinear.

How many Straight line can be formed by joining 12 points, 4 of which are collinear.

How many triangles may be formed by joining any three of nine points on a plane when five of them are collinear.

How many triangles may be formed by joining any three of nine points on a plane when no three of them are collinear.

How many triangles may be formed by joining any three of the nine points when five of them are collinear?

How many straight lines can be drawn by joining 15 distinct points on a circle ?

How many triangles may be formed by joining any three of the nine points when no three of them are collinear ,