A figure must be selected before it can be deleted. To delete a selected figure, touch and hold anywhere in the drawing canvas for ~1 second or press on the Contextual Menu Button to bring up the Contextual Menu and press on the Delete option.
Pressing on the Delete Button located in Top Toolbar is an alternative method for removing a selected figure.
Please keep in mind that TouchDraw has support for Undo and Redo. If a figure is deleted by accident, press the Undo Button in the Top Toolbar to redisplay the object.