Which statement is true about the graphs of the two lines y=-6 and x= 1/6 The lines are perpendicular to each other because the graph of y=-6 is a horizontal line with a slope that is undefined, and the graph of x= 1/6 is a vertical line with a slope of 0. The lines are perpendicular to each other because the graph of y=-6 is a vertical line with a slope that is undefi and the graph of x= 1/6 is a horizontal line with a slope of . The lines are perpendicular to each other because the graph of y=-6 is a vertical line with a slope of 0, and the graph of x= 1/6 is a horizontal line with a slope that is undefined. The lines are perpendicular to each other because the graph of y=-6 is a horizontal line with a slope of 0, and t graph of x= 1/6 is a vertical line with a slope that is undefined.