Use a protractor to draw an obtuse angle ${120}^{\mathrm{o}}$.

If $\mathrm{AB}=5 \mathrm{cm}$, which of measures is correct in the given figure.

                     $\left(I\right)$                                                                   $\left(II\right)$

                    $\left(III\right)$

A line through two endpoints $\text{'}\mathrm{A}\text{'}$ and $\text{'}\mathrm{B}\text{'}$ is denoted by ______.

A line segment from point $\text{'}\mathrm{B}\text{'}$ to point $\text{'}\mathrm{A}\text{'}$ is denoted by _____.

A ray has a _____ endpoint$\left(\mathrm{s}\right)$.

How many line segments are there in the given line? Name them.