Draw line segments with the Pen tool

Select the Pen tool.

Position the Pen tool where you want the straight segment to begin and select (without dragging) to define the first anchor point. The first segment you draw will not be visible until you select a second anchor point. 

Select again to specify the position where you want to end the segment.

Continue selecting to set the anchor points for additional straight segments.

To close the path:

• Position the Pen tool over the first anchor point, which appears hollow. When positioned correctly, a small circle appears next to the Pen tool pointer  . 
• Select or drag to close the path. 

To leave the path open: 

• Ctrl-click (Windows) or Command-click (macOS) anywhere away from the path. 
• Select a different tool or select  Select > Deselect.