Distinguish between a triangle and its triangular region.

In following figure, $D$ is a point on side $BC$ of a $△ABC. AD$ 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.

Explain the term: Triangle
 

Explain the term: Parts or elements of a triangle 

Explain the term: Scalene triangle
 

Explain the term: Equilateral triangle