Perimeter Tool

measure icon

Call this from Edit > Tools > Measure and choose Perimeter Tool from the drop-down list. A dialog box with three tabs appears; make choices in the Settings and Mark up panels, then draw a set of lines or a closed shape over an object in the PDF whose perimeter you want to measure.  Click to change line direction, click to confirm the last line, then right-click and choose Complete Measurement from the shortcut menu to finish drawing and measuring an open shape, or double-click to have the program add the last line to close the shape.

View tab
 

Measurement shows:

In Cursor Location, the X and Y coordinates of the current cursor position are dynamically displayed relating to the start points of the current line section. No signs are considered.

 

Setting tab

Markup tab