Line segments can be created freely in three dimensional space and are piece-wise linear.
Select Create, Draw Curves. Select the Line option from the provided submenu. This will be the default segment type applied when
the Draw Curve panel opens. Define the two necessary points for the new curve to be created. When the new curve is complete, click OK to
save it and close the panel, or click Apply to save the curve and continue on to the next new curve.