Creating the tangential center

1. Choose the option Line, located in Geometry Create Line. On the mouse menu, choose Contextual and use Join C-a to select points (0, 0) and (0, 25). Press ESC.

2. In the Copy window, choose Rotation from the Transformation menu and Lines from the Entities Type menu. Enter an angle of 120 degrees, thus rotating the last line created 120 degrees.

3. In the Copy window, choose Translation from the Transformation menu and Lines from the Entities Type menu. The translation vector for the translation to be made is the line just created. As the first point of the translation, select the point farthest from this line segment. For the second point, select the other point of the line. (Figure 5)

Figure 5. The line segment selected is the tranlation vector.

Figure 6. Result of the translation with copy

4. Click Select to select the line segment that forms an angle of -60 degrees with the horizontal. Press ESC to indicate that the selection has been made.

5. Choose Geometry Create Intersection Line-line.

6. Select the two inner lines.

7. Click Yes to confirm that there is an intersection and that, therefore, the shortest distance between the two entities is 0. The intersection between the two entities (lines) creates a point. This point will be the tangential center.

8. Press ESC to indicate that the process of intersection between lines is finished.

Figure 7. The auxiliary lines

NOTE: The option Undo enables the user to undo the operations most recently carried out. If an error is made, go to Utilities Undo; a window comes up in which to select all the options to be eliminated.