Answer:
Mark as BrainlistStep-by-step explanation:
We know that joining of any 2 points give a line. Thus the number of lines obtained from 10 points, when no 3 of which are collinear =
10
C
2
=45
Lines obtained from 4 points =
4
C
2
=6
No of lines lost due to 4 collinear points =6−1=5
So required number of lines =45−5=40
Also we know that any triangle can be obtained by joining any 3 points not in the same straight line. Thus number of triangles obtained from 10 different point, no 3 of which are collinear are =
10
C
3
=120
Triangles obtained from 4 points =
4
C
3
=4
Number of triangles lost due to 4 collinear points=4
So required number of triangles =120−4=116