Answer
(a) Yes
(b) Yes
(c) No
(d) Yes
Refer to the step by step part for the explanation.
Work Step by Step
RECALL:
(i) The graph of $y=k$ is a horizontal line and has a slope of 0.
(ii) The graph of $ =h$ is a vertical line and has undefined slope.
Thus,
(a) Yes.
The line is horizontal because the equation is of the form $y=k$.
(b) Yes.
The line is vertical because the equation is of the form $x=h$.
(c) No.
A line perpendicular to a horizontal line is a vertical line.
A vertical line has an undefined slope.
(d) Yes.
A line perpendicular to a vertical line is a horizontal line.
A horizontal line has a slope of 0.