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In order to convert this sketch into the stepped shaft that is required, it must be rotated around the Y axis. Since the sketch is now complete, select the Pull tool in the Edit section of the toolbar. Utilize the Revolve feature by picking the Y axis to rotate about. Rotate the view slightly to see the yellow, curved arrow, then drag with your mouse to pull the sketch around the Y axis. Press the spacebar and enter “90deg” to achieve the precise rotation needed. It should look like the object in the picture below.
Click in a blank spot of the model window, or press the Esc key on your keyboard, to complete the Pull operation.