While in a 3D View, all axes are accounted for while creating the dimension
• Select View > Home from the drop-down menus
• Create a cube, height 1’
• Create another cube, height 3’
• Use the Linear Dimension tool to measure between a point from each of the cubes.
• The dimensions will measure the distance between the XYZ coordinates of the two points
• While in a 2D view, only the two visible axes will be used in the measurement
• Use the same cubes as before
• Enter Top view
• Use Linear Dimensions as before to create a dimension between a point from each cube
• Before confirming the location of the dimension read-out, move the cursor along the X-axis, then the Y-axis. Notice that your cursor placement dictates the length of the measurement. If your cursor is along the X-axis, it will only account for the distance along the Y-axis, and vice versa. If the points measured are not aligned along an axis, then you can also move your cursor perpendicular to the measurement points to measure the distance between the XY coordinates.
• If you now orbit (Set View) to enter a 3D view, you’ll see that the coordinates are automatically aligned with the XY plane.