A horizontal line is a straight line that runs from left to right, remaining at a constant height above or below the horizontal axis. It has a slope of zero, meaning there is no upward or downward inclination. Visually, it appears as a flat, straight line parallel to the x-axis in a Cartesian coordinate system. This type of line can be represented by an equation like (y = c), where (c) is a constant.
a straight line
A curved line is a line that is curved.
A linear line is a straight line
a line across
If the line has ends, then it's a line segment.
The plumb line is a vertical straight line.
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a line
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a line graph looks like a stocks chart
It looks like this////