What is a common application for a transit-level?

A transit-level is primarily used for determining elevations and establishing horizontal planes, which makes it an essential tool in various construction and surveying tasks. When calculating elevations, the transit-level allows for precise measurements to ensure that structures are built to the correct height and in alignment with existing grade lines. This capability is particularly important in pipe fitting applications where proper elevation of pipes is critical to ensure effective drainage and flow.

Although creating straight lines (first choice) can be accomplished through a transit-level by sighting along a level line, it is not the primary purpose of the tool. Measuring pipe lengths (third choice) does not utilize a transit-level directly, as pipe lengths are typically measured using tape measures or specialized pipe measuring devices. Cutting angles (fourth choice) would require tools such as miter saws or pipe cutters that are designed for precise angle cuts rather than an elevation-measuring tool like the transit-level.