A kilometer is defined as a 1000meters. So substitute 1000meters for kilometers and you have 18*(1000 meters) = 18,000 meters.
5.49 meters.
0.5
None. 200 square metres is a measure of area - in 2-dimensional space. A length is a measure in 1-dimensional space. The two measure different things and it makes no sense to try to convert from one...
18 inches=0.4572