1. First, we open a new CAD document for demonstration, and click the "Curve" button to start drawing curves.
2. Of course, you can also click "Drawing" in the menu bar, and then select "Spline Curve" button in the drop-down menu.
3. Specify the first point on the screen and start drawing the curve, and specify the second, third and fourth control points to control the radian of the curve in turn. You can specify more control points to draw the curve you want.
4. At the end of the curve, right-click to confirm, and you will be asked to specify the tangents of the starting point and the ending point. If there is no need to modify it, we just need to double-click the right mouse button.
5. In this way, the curve is drawn.