Drawing rectangular holes is very simple and it works in the same way as in the case of creating rectangular areas on the map. Choose a place on the map that will be one corner of your hole, tap and drag the rectangular to the desired size, release, and the hole will be cut. Is the rectangular fragment that you want to cut ready? Tap "Save hole(s)" to save changes. If you want to cancel the hole you cut, just tap "Cancel changes" and the cut out will return to the map.