The Tool Control Bar is docked below the toolbar. It is context sensitive: when a tool is activated, the tool control bar shows the tool specific options. Or, when an object is selected, the tool control bar shows tools which are specific to that particular object type.
If the contents of the control bar do not fit inside the visible area, you can scroll it by dragging it with the right mouse button 'Ctrl' key held down, or with the middle mouse button.
The tool control bar can be hidden and made visible from the pull down menu View/Control bar or with the hotkey 'F4'.