To Change a Tangent's Length Constraint
1. Open the Style feature that contains the curve you want to edit.
2. Perform one of the following operations:
◦ Select a curve, right-click, and choose 
Edit Definition from the shortcut menu.
Edit Definition from the shortcut menu.◦ Click 
Style > 
Curve Edit and select a curve.
Style > Curve Edit and select a curve.The Curve Edit tab opens.
3. Select an endpoint to display the tangent vector for a curve with interpolation points. For curves with control points, select the segment adjacent to the endpoint.
 | Tangent and Curvature types support length constraint modification. |
4. On the Tangent tab under Properties, select an option:
◦ Fixed length to set a fixed value for the tangent length. Then next to Length, enter a value.
◦ Proportional length to set the tangent length to be a proportion of the natural tangent length. Then next to Stretch, enter a proportion of the natural tangent. The value can be any real number, but not zero. The default value is 1.00.
5. Click 
.
.