Loot at the following figure and fill in the blank.

  
Vertex of $\angle 1$ is .

Loot at the following figure and fill in the blank.

  
Vertex of $\angle 2$ is _____.

Loot at the following figure and fill in the blank.

  
Common points on $\angle 1$ and $\angle 2$ are  _____.

Choose open or closed for the following curve.

Choose open or closed for the following curve.

Choose open or closed for the following curve.

Choose open or closed for the following curve.

Look at the given polygon and answer the following question.

How many sides are there in the polygon?

Look at the given polygon and answer the following question.

Name all its vertices.