ClipArt ETC
Illustration of perpendicular lines with the horizontal and vertical lines labeled. "A horizontal line is a line parallel to the horizon, or water level. A vertical line is a line perpendicular to a horizontal line; consequently, it has the direction of a plumb-line."

Perpendicular Lines With Horizontal and Vertical Labeled

Illustration of perpendicular lines with the horizontal and vertical lines labeled. "A horizontal line…