How many triangles are there in the following figure ?
Solution
From the given,
We know that If any triangle have the same base and n middle line then it always make n+1 triangle.
So, here in this image after breaking up the diagram which is given in the question, we can see that there is 5 such triangle in which have one middle line. Hence, number of triangle can be formed =3+3+3+3+3=15 triangle.
