To draw a line tangent to a curve

1. Click the Line Tangent to Curve icon, or choose Line Tangent & Perp > Line Tangent to Curve from the Keypoint Curve Toolbox.
2. Click the start point of the tangent line.
3. Click the curve you want the line to be tangent to.

   The Line Tangent to Curve tool calculates the end point for the line to be tangent to that curve.

   • If it cannot find a tangent, it prints a message in the prompt line.
   • If it finds more than one tangent, it uses the tangent closest to where you clicked.