When you create or edit a sketch, you work in the sketch environment. The sketch environment consists of a sketch and sketch commands. The commands control the sketch grid and draw lines, splines, circles, ellipses, arcs, rectangles, polygons, or points.
Using the default settings, a 2D sketch is not active when you begin a new part file. Click 2D sketch and then select a plane to enter the sketch environment. When you begin a sketch, the Sketch tab is active and the sketch commands are available. You can control the initial sketch setup by using template files, or settings in the Application Options dialog box, Sketch tab.
When you create a sketch, a sketch icon displays in the browser. When you create a feature from a sketch, a feature icon displays in the browser with the sketch icon nested under it. When you click a sketch icon in the browser, the sketch is highlighted in the graphics window.
After you create a model from a sketch, re-enter the sketch environment to change or start a new sketch for a new feature. In an existing part file, first activate the sketch in the browser. This action activates the commands in the sketch environment. You can create geometry for part features. The changes you make to a sketch are reflected in the model.