An aligned dimension is similar to a linear dimension, except it tilts to the same angle as the element you are dimensioning, making it the ideal choice for elements that are not horizontal or vertical.
To create aligned dimensions:
Select Tools
> Dimensions > Aligned Dimensions, or click the Aligned Dimensions
button on the Notation toolbar.
Click a point in your drawing to begin the dimension line.
Move your mouse (you do not have to hold the mouse button down) to a second point and click. A dimension line including offsets, arrows and a numerical value is added to your drawing.
Move your mouse away from the dimension line to stretch your extension lines. When the extension lines are the desired length, click to finish the dimension.