Drafting standards for termination symbols differ. AutoCAD LT provides seven standard types of arrowheads. You can apply a different type to each end of the dimension line and control the size of each. The first arrowhead is displayed in the left image tile in the dialog box and the second in the right. The order of arrowheads is determined by the order of extension lines. The first extension line is where you specified the first extension line origin when creating the dimension. For angular dimensions, the second extension line is counterclockwise from the first. Leader lines use the first arrowhead only (see Creating Text with Leaders).
The first arrowhead type automatically applies to the second arrowhead unless you select a different type for the second arrowhead. You can choose not to use any arrowheads or to use one arrowhead only. You can also create your own arrowheads (see Creating and Modifying Custom Arrowheads).
You can choose oblique stroke arrowheads for both ends of the dimension line and set the stroke size. Oblique strokes, also known as tick marks, are short lines drawn where the dimension line meets the extension lines and at a 45-degree angle to the dimension line.
When using oblique strokes, you can specify the distance that the dimension line extends past the extension line (see Modifying Dimension Lines in Controlling Dimension Geometry ).