Answer: 18
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Step-by-step explanation:
2 cm on paper (or on screen) represents 3 meters in real life.
The backyard is 2 cm horizontally across on the screen, so it's 3 meters across in real life. This is the shorter dimension.
The longer dimension is 6 meters. We can think of it like this
2 cm : 3 meters
2*2 cm : 2*3 meters .... multiply both sides by 2
4 cm : 6 meters
The real backyard is 6 meters by 3 meters to give an area of 6*3 = 18 square meters.