AutoCAD 2018 and Inventor 2018 Tutorial By Tutorial Books (www.engbookspdf.com)

Part 1: AutoCAD Basics
Click Annotate > Centerlines > Centerline on the ribbon.
Select two lines which are parallel or non-parallel to each other; a
centreline is created between them.
Change the position of the lines; the centreline also changes.
Ordinate
DOR
It creates ordinate dimensions based on the current position of the User
Coordinate System (UCS).
Click Annotate > Dimensions > Dimension drop-down >
Ordinate on the ribbon.
Select the point of the object.
Move the pointer in the vertical direction and click to position
the X-Coordinate value.
Select the point of the object.
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