The lines are perpendicular to each other because the graph of y = –6 is a horizontal line with a slope of 0, and the graph of x = is a vertical line with a slope that is undefined.
A horizontal line always have a constant value of y. It doesn't move up or down. A vertical line always have a constant value of x. It doesn't move right or left.
The lines are perpendicular to each other because the graph of y = –6 is a horizontal line with a slope of 0, and the graph of x = is a vertical line with a slope that is undefined.