Drawing a Tangent Line on a Sketch Plane

  1. Click Tangent Line in the Sketch group.
    The tool is disabled if there are no curves or lines in the sketch plane.
  2. Click the curve you want to draw tangent to.
  3. As you move the mouse, the start point moves so that the line remains tangent to the curve.
    The tangency indicator shows you how the new line will be tangent with existing geometry if you click the current cursor location.
  4. (Optional) Dimension the line with a length.
    You cannot dimension from another sketch object when creating a tangent line.
  5. Click to set the end point of the line.
    If you move your mouse over another curve, the line snaps so that it is tangent to the second curve. Hold Alt to stop your cursor from snapping to curves.

The common sketch options are described in Sketch Tool Guides and Options.