To Create Curve Connections Using Tangent Constraints
1. Click 
Style > 
Curve Edit. The Curve Edit tab opens.
Style > Curve Edit. The Curve Edit tab opens.2. Select a curve and click its endpoint to display the tangent vector.
3. Perform one of the following operations:
◦ Right-click the tangent vector and choose a tangent constraint from the shortcut menu
◦ Click the Tangent tab. Under Constraints, select a primary tangent constraint from the First box.
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.
 | By definition, a Natural tangent has a proportional length. |
5. Type values for the tangent attributes.
| | • You can specify elevation only for Free curves. When changing constraints, use the horizontal or vertical axis of the datum plane. • If the value of the tangent elevation angle is 90 degrees, modifying the tangent angle has no effect on direction. The elevation controls the tangent direction. • A draft measurement is available when you apply a Draft Tangent. |
6. Click 
.
.