- Choose the Zoom->In option from the mouse menu. Magnify the right end of the model and rotate the view to facilitate the selection.
- Set "union" as current layer to use, with a <Double-click>
- From the Copy window, select Lines and Rotation . Enter an angle of 120 degrees and select the rotation center (160, 25) as First point. Since the rotation may be done in 2D, choose the option Two dimensions . From the Do extrude menu, select Surfaces and be sure that Multiple copies is 1 and Maintain layers is unset, then the new entities will be created in the layer to use instead of the layer of the source curves.
- Click Select and select the four lines that define the right end of the pipe (see figure above). Press ESC when the selection is finished.