Floppy disk B in the rectangle we just drew right click on the pop-up menu, select "Ungroup", so we have just drawn the rectangular box to convert to a pure path, so that we can further modify.
C slightly enlarge the canvas zoom to 200%, then drag the slider at the edge of the workspace, position our gaze to the top right corner of the rectangle box, and then select the Pen tool on the toolbar and add two nodes to the rounded corner attachment:
D Keep the two newly added nodes and press the Keyboard del key to delete the two nodes that were used to fillet, resulting in a bevel:
E on the top of the rectangular disk, and then draw a long narrow rounded rectangle, select the menu item "modified" under the "Combination path >>> punch", in the top edge of a notch to:
F Application of the previous steps of the production method, we can be a rounded rectangle of the edge contour of a more detailed modification, and finally achieve the floppy disk body contour simulation results: