Given:
The slope of the given line is zero.
a) parallel line: Parallel lines have the same slope. Any line whose slope is x=zero will be parallel to line y=-6.
So, one equation can be,
2) Perpendicular line
Clearly the line y=-6 is the horizontal line having a slope of 0.
So, the line perpendicular to this line will be a verticle line with an undefined slope.
And its equation is of the form x = a.
The equation can be,
c) The lines which are neither parallel nor perpendicular will be just the intersecting lines.
The equation can be,