To Create a Sketched Datum
1. Create or open a sketch with one or more points, regular lines, or construction lines. The entities appear on the Model Tree.
2. Right-click one or more points or lines on the Model Tree and click Convert to Datum. The selected entities are converted to sketched datum entities.
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If you select entities other than points and lines for conversion, the Convert to Datum command is unavailable on the Model Tree shortcut menu.