An irrigation canal measures 12cm. in a NAMRIA Map Sheet of 1:50000 scale. Determine the ground distance.
\[
MS = \frac{MD}{GD}
\]
\[
\frac{1}{50000} = \frac{12cm.}{GD}
\]
\[
GD = 600000cm. [\frac{1m.}{100cm.} (\frac{1km.}{1000m.})]
\]
\[
MD = 6km. \leftarrow \text{answer}
\]