Build the pocketed plate
The three views below show a plate with a pocket milled into its top face. The pocket reaches no edge of the plate, so it never breaks the plate's outline: the top view shows it as a rectangle drawn INSIDE that outline, and the other two views show it only as dashed lines. Work out its position and depth from those, then cut it.
The part, in three views
corner 1 of 4
Click a face to cut that block away. Right-click to put a block back. Use Turn left/right to walk around the part: a feature on the far side cannot be reached from here.