If Arjun has a quadrilateral ABCD, how many triangles are there in the quadrilateral such that one of the diagonal forms one of the sides of the triangle?
4
Consider the quadrilateral ABCD above.
The triangles that can be constructed with diagonals as one of the sides are as follows - △ABC, △DBC, △BAD, △CAD.
Hence, 4 triangles are possible.