The dimension projection line does not break where it intersects another dimension that is already broken. Nor does it break for annotations.
Right-click a dimension where you want to add projection line breaks.
On the dimension shortcut menu, choose Add Projection Line Break.
Tip:
You do not have to update the drawing view to display the breaks.
Repeat for each dimension you want to break.
Tip:
To adjust the break gap, type a new value in the Break box on the Lines and Coordinate page of the Dimension Properties dialog box and click OK.
To add a break around dimension text that intersects other dimensions, set the Fill Text With Background Color option on the Text page of the Dimension Properties dialog box.
To remove dimension projection line breaks, use the Remove Projection Line Break command on the dimension shortcut menu.
You also can choose Edit→Undo and Edit→Redo for breaks that you have just added.