Add a Tangential Constraint

1. Select Sketch | Constraints | Add tangential constraint.
2. Select the first line. This line keeps its position.
3. Select the second line. This line moves so that it is tangent to the first line.
4. Add more tangential constraints by repeating steps 2 and 3 or finish adding tangential constraints by pressing the ESC key or the middle mouse button.

If the result was not what you expected, you can change the side of the tangential constraint after defining it.