Creating a parabola given two points and two tangency conditions

The 2 points and 2 tangents method of the Parabola command enables you to create a parabolic arc defined by its two endpoints and the tangency conditions at those points. After specifying the endpoints, you can specify the tangency conditions by selecting existing lines, indicating points or using the specific handles.

After starting the Parabola command, proceed as follows.

1	In the Type drop-down list, select 2 points and 2 tangents.
2	Specify the two endpoints of the parabolic arc by clicking or by using a snap command. To change the selected points, right-click on Points, select Reset in the context menu and specify the new points.
3	For each of the two endpoints, specify the tangency condition in one of the following ways: In the 1st Tangent and 2nd Tangent drop-down lists under Tangents Group, select the desired direction (see " How to define an axis or a line" for details). Use the handles: The three arcs represent the three angles of revolution (about X, about Y, about Z). You can rotate the tangent vector about an axis by dragging the corresponding arc or by typing the value of the rotation into the Angle box which shows up when you pick the arc. The longest red line represents the tangent vector: you can pick its free endpoint and move it around in the space until you assign the tangent vector the desired direction.
4	Click or to confirm your selections and create the curve. Click to discard your changes.