Creo Interactive Surface Design (Style) > Connections > Curve Connections > To Create Curve Connections Using Tangent Constraints
  
To Create Curve Connections Using Tangent Constraints
1. Click 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 Fix Length or Relax Length.
 
* By definition, a Natural tangent has a relaxed 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 .