Polyline

    A polyline is a sequence of line segments which is create as a single object.
A polyline indicates that two or more lines are joined.
Sort cut key of Polyline is “PL”

    For Polyline we have to do

           Click Home -> Draw -> Select polyline -> Give starting point ->  last point.

   Construction line

A Construction lines also known as xlines, Construction lines help to draw small or   detailed parts of the design on a single sheet, short cut key of construction line is “XL”.

          Click Home tab -> Draw panel -> Construction Line

  1. Specify a point to define the root of the construction line.
  2. Specify a second point through which the construction line should pass.
  3. Press Enter to end the command