To create a recess or protrusion adjacent to a curved shape:
Let’s assume Z = 0.4 for the outer rectangle and that all but the Z = -0.2 notch is already drawn.
- At the location of the notch draw a rectangle extending past the left edge of the outer rectangle and past the large arc.
- Choose Edit | Select All.
- Click the Repeat button.
- Nudge the copy fully away from the original, using the arrow keys.
- Choose Line | Intersect.
- Remove all lines except the shape corresponding to the arced notch.
- Group the lines of the notch.
- Set Z to -0.2.
- Delete the original notch rectangle.
- Nudge the arced notch into place.
- Choose View | 3D.