Construction Ellipse Centered at Node, through Node, Tangent to Line

1. Call the Ellipse command.

2. Make sure that the following automenu option is active:

3. Select a 2D node to be used as the center of the ellipse. A node may be selected in one of the following ways:

•Press or <Enter>, while the cursor is within drawing window, in order to select a node nearest to the cursor.

•Move the cursor over an intersection of construction lines or a characteristic point of a graphic line, using object snappings, and press or <Enter>. A connected 2D node will be created automatically at the specified point.

•Activate the following automenu option:

If the option is activated via keyboard, then the node nearest to cursor gets selected instantly.
If the option is activated via mouse, then you have to additionally press within drawing window for selecting the nearest node.

4. Select a 2D node for the ellipse to pass through. The first semi-axis of the ellipse will connect such node with the node selected on the previous step. A node may be selected in one the ways described above.

5. Select a straight construction line for the ellipse to be tangent to. The length of ellipse's second semi-axis will be calculated so, that it ensures tangency of the ellipse to such line. A line may be selected in one of the following ways:

•Move the cursor over the desired line, using object snappings, and press or <Enter>.

•Activate the following automenu option:

If the option is activated via keyboard, then the line nearest to cursor gets selected instantly.
If the option is activated via mouse, then you have to additionally press within drawing window for selecting the nearest line.

During line selection, the preview of the ellipse follows the cursor within the area limited by the length of the first semi-axis. When the cursor is outside this area, the preview is not displayed and elements selection is impossible.

After creating an ellipse the command returns to the initial state.