Autocad divides dimensions into four main categories: Linear, Radial, Ordinate and Angular.

Linear dimensions are usually for a line, or straight segments of a polyline. We can also use the linear dimensions for arcs and circles,

we will get a linear arc length and diameter of the circle.

Create a linear dimension, horizontal lines vertically, or rotate the dimensions.

This command replaces the command and DIMVERTICAL DIMHORIZONTAL.

Steps we have to do is:

From the Ribbon: Home tab> Annotation panel> Dimension drop-down> Linear

From the Menu: Dimension> Linear

From the Toolbar: Dimension