Final answer:
To find the actual length of the room on a floor plan, we need to convert the measurement using the scale factor. In this case, the actual length is 18 meters.
Step-by-step explanation:
To find the actual length of the room, we need to convert the measurement on the floor plan to meters using the given scale. The ratio of the floor plan to the actual measurement is 1cm:3 meters. Since the room is 6cm long on the floor plan, we can calculate the actual length as follows:
Actual length = floor plan length x scale factor
Actual length = 6cm x 3m/cm
Actual length = 18 meters
Therefore, the actual length of the room is 18 meters.