Distinguish between a triangle and its triangular region.

In Figure, $\mathrm{D}$ is a point on side BC of a $△ABC$. $\mathrm{AD}$ is joined. Name all the triangles that you can observe in the figure. How many are they?

In the given figure, $A, B, C$ and $D$ are four points, and no three points are collinear. $AC$ and $BD$ intersect at $O$. There are eight triangles that you can observe. Name all the triangles.