The lengths of $6$ line segments are $2, 3, 4, 5, 6, 7$ units respectively. The number of triangles that can be formed using these line segments is ......

$A$ parallelogram is cut by two sets of $m$ parallel lines,each set being parallel to one of its sides. How many parallelograms are formed in total?

There are two women participating with some men in a chess tournament. Each participant played two games with every other participant. The number of games that the men played between themselves is $66$ more than the number of games that the men played with the women. Find the total number of participants in the tournament.

Find the number of marked points on the plane,if when connected pairwise by line segments,the total number of line segments formed is $15$.

In a plane,there are $37$ straight lines,of which $13$ pass through the point $A$ and $11$ pass through the point $B$. Besides,no three lines pass through one point,no line passes through both points $A$ and $B$,and no two lines are parallel. The number of intersection points the lines have is equal to:

If a polygon of $n$ sides has $275$ diagonals,then $n$ is