The device most often used to orient a surface so it is either parallel or perpendicular to the ground is a __________.

The device that is most often used to orient a surface so it is either parallel or perpendicular to the ground is a spirit level. This tool utilizes a sealed tube with a liquid and an air bubble. When the tool is placed on a surface, the position of the bubble in relation to the marked lines on the tube indicates whether the surface is level. If the bubble is centered between the lines, the surface is perfectly level (parallel to the ground). If used on a vertical structure, it helps determine plumb, which means the surface is perpendicular to the ground.

Measuring tapes are primarily used for measuring length and distance, and while they can assist in layout and alignment tasks, they do not provide information about the angle of a surface relative to the ground. A plumb bob is a weight attached to a string that can help ascertain vertical alignments but does not directly indicate whether a surface is level. Laser alignment devices are more advanced tools used for precise alignment tasks but are not as widely employed for basic leveling of surfaces as a spirit level is.