Depending on the plugins activated, a certain number of shape buttons are stacked on the left of the toolbar. Once clicked, these let you draw various shapes on the canvas such as points, line segments, or freeforms. See the [Problem Configuration Plugins] (probconfig_plugins.md) for their usage.
Once this button has been clicked, any shape drawn on the canvas can be selected. Its color will change to a dimmer value of its non-selected state. A group a shapes can be selected if the [SHIFT] key is held down while clicking multiple shapes. Any click outside a shape or group of shapes will deselect everything. A subsequent and immediate drag, after defining a selection, will move the totality of the shapes in the direction of the drag. If one of the members of a selection hits one of the boundaries of the canvas, the selection will stop moving in that direction; thus distance between members of the selection and its overall shape is preserved.
Once this button has been clicked, any selected shape (or group of shapes) will be deleted from the canvas.
Repeatedly clicking these will undo/redo actions such as shape creation and displacement.