To Create a Section
Using this topic, you can create a sketch-based feature that uses an independent section. This section is not associative with any Sketch feature. If you want to create a dependent (associative) section refer to the To Select a Sketch Feature topic.
1. Click the sketch-based feature tool. The tool tab opens.
2. Perform one of these actions:
Click Define from either the Placement or Reference tab, depending on the tool used.
Place your pointer in the graphics window, right-click, and select Define Internal Sketch from the shortcut menu.
The Sketch dialog box opens.
3. Define the sketch plane and the sketch orientation, and click Sketch. The Sketch tab opens and the model orients.
4. Sketch and constrain the desired section. Make sure you include any feature specific requirements, such as a closed loop, vertical axis, or a coordinate system.
5. After the sketch is complete, click OK on the Sketch tab. The sketched-based feature tool resumes, and preview geometry appears in the graphics window. Notice that an independent section is created and placed in the Sketch collector on the feature tab and in the Model Tree (under the new sketched-based feature).
6. Continue designing the sketch-based feature as necessary.
7. After you finish, click . The sketch-based feature and the section are created, and the tool closes. Remember that this section is not associative with any Sketch feature.
* 
You can always identify the section type from the Model Tree. Dependent sections share the same name of the parent Sketch feature. Independent sections have unique names.