1No bhaiya according to d book they say n-1C2
There are n concurrent lines and another line parallel to one of them.Find the number of different triangles that will be formed by the (n+1) lines..
-
UP 0 DOWN 0 0 3
3 Answers
62Chose any 2 concurrent lines .. you will get one triangle...
the answer should be nC2
1from the n concurrent lines the line which is parallel to our excluded line won't be counted as we cannot form a triangle with two parallel lines
by fixing the seprate non-concurrent line. as three concurrent lines cannot form a triangle .
we have to select 2 line from the rest (n-1) concurrent lines.
n-1C2