Type the list of points $\left[\left[1\,2\right]\,\left[3\,7\right]\,\left[4\,-2\right]\right]$ 

Context Panel:
Curve Fitting≻Interactive Curve Fitting≻x (as variable)
     Splines≻ Degree of the spline: 1
     Plot
     On 'Done" return Plot
(See Figure A-9.8(b).)

Write a list of given points.

Context Panel: Plots≻Plot Builder

Press the Options button (See the figure beneath this cell.)

In the Options pane, change Style to line.
(See the figure diagonally down from this cell.)

Press the Plot button to obtain the graph shown to the right.

Enter the list of points.

$L≔\left[\left[1\,2\right]\,\left[3\,7\right]\,\left[4\,-2\right]\right]\:$

Graph the polygonal line through the points.

$p_1≔\mathrm{plot}\left(L\,\mathrm{style}\=\mathrm{line}\right)\:$

Graph the points.

$p_2≔\mathrm{plot}\left(L\,\mathrm{style}\=\mathrm{point}\,\mathrm{symbol}\=\mathrm{solidcircle}\,\mathrm{symbolsize}\=20\right)\:$

Combine the graphs of the polygonal line and the points.

$\mathrm{plots}\left[\mathrm{display}\right]\left(p_1\,p_2\right)$