Find the number of triangles in the given figure.

NA

All the components of Question Figure form Answer Figure(4)

Fold the paper from left to right, then from down to up.
or Fold the paper from right to left, then from up to down.

Except figure (3), in all other figures the three designs have been shaded differently.

According to above given figure , we can see that
The mirror image always be opposite to the original image across the given line. While given image will become opposite to the given mirror MN.

The three small circles get arranged in the middle of the triangle and three lines extend from the three vertices of the triangle.

On the basis of following pattern in given dices , we can say that
Ten block are visible and four block are invisible.
From the diagram it is clear that there are 14 blocks.