2.0 inches times 4 feet/inch
8 feet
The inches cancel top and bottom and you end up with 8 feet.
This is not a unit conversion really. It is more likely a scale drawing.
For example if my drawing of my room floor is 5 inches by 6 inches
the floor would be
5 inches * ( 4 ft/inch) = 20 feet
by
6 in * 4 ( ft/in) = 24 ft