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Water represents a blue line on a map.
The blue line on a map usually represents a stream of water!
the blue line represents Lakes, Streams , canal and mainly just water
the blue line represents Lakes, Streams , canal and mainly just water
Usually represent a stream, river, or other body's of water.
a river
A blue line with triangles is commonly referred to as a "blue dashed line" or "blue dashed triangle line." In graphics and design, it may represent a boundary, a path, or a guiding line, depending on the context. The triangles can indicate direction or movement along the line.
'altitude' or perpendicular. If on line is the base (horizontal) line, then the line that is a 90 degrees to it is the perpendicular/altitude.
Altitude
If the slope of a line is m then the slope of an altitude to that line is -1/m.
A stream,river or another body of water.
The Black-Blue-Black design is usually seen on a policeman's personal car or family members car. It stands for the "thin blue line".