If the points (1,2), (0,0) and (a,b) are collinear, then the area of the triangle formed by these points is ____.
3
2
1
0
The points (a + b, c), (b + c, a) and (c + a, b) are collinear, then area of triangle formed by then is:
110 triangles can be formed by joining 10 points as vertices, in which n points are collinear. Then the value of n is