Triangular outlet / electrical outlet

There are not enough outlet for those plugs, or the line on the plug is too short to reach the outlet. Above are all problems that might happen in house and office. We must buy another extension cable, and it becomes another problem, how to storage them is troublesome.
Triangular oulet combine the extension cable with the outlet, and become a kind of extension cable that embed in wall.Having the same appearance as the normal one, just press the button when we need it, and it can pull out extension cable from the outlet. With the triangle appearance, it can prevent those plugs from extruding each other because of the different sizes.