To Create a Datum Point on a Curve, Edge, or Datum Axis
1. Click Model, click the arrow next to Point, and click 
Point. The Datum Point dialog box opens.
Point. The Datum Point dialog box opens.2. Select an edge, datum curve, or axis. A default point is added to the selected entity in the graphics window, and the new point is added to the point list. The selected entity appears in the References collector.
3. Adjust the point's location using one of these methods:
◦ Drag the placement handle on the point to position it manually.
◦ Position the point using the Placement tab. Set the offset by selecting an option:
▪ End of curve—Offsets the new point’s position from the end point of the selected curve or edge. To offset from the other end, click Next End. Set the offset distance by selecting an option:
▪ Ratio—Determines the offset distance as a fraction of the distance from the datum point to the selected endpoint in relation to the total length of the curve or edge. For example, entering the offset ratio of .25 places a datum point at 1/4 of the curve's length from the selected endpoint.
Type a ratio value from 0 to 1 in the Offset box.
▪ Real—Uses a distance value to measure the offset distance from the selected curve or edge end point to the new point.
Type a distance value in the Offset box.
▪ Reference—Offsets the new point’s position from a selected entity. Select a reference entity, for example, a solid surface.
4. Click New Point to add more points, or click OK.