Which instrument can measure vertical angles?

The instrument that effectively measures vertical angles is the theodolite. A theodolite is an optical instrument that allows for the precise measurement of angles in both the horizontal and vertical planes. It is commonly used in surveying, engineering, and construction to establish accurate points and lines, which is essential for various layout tasks and construction projects.

While the transit is also capable of measuring angles, including vertical angles, it has largely been replaced by the more advanced theodolite in modern applications. The key distinction is that theodolites provide higher accuracy and more detailed measurements compared to traditional transits, making them the preferred choice for precise angle measurement in various professional fields.

Laser levels and plumb bobs, on the other hand, are tools used for leveling and ensuring verticality, but they do not measure angles. Laser levels project a laser beam to create a horizontal or vertical line, while a plumb bob uses gravity to find a true vertical line. Therefore, while they serve important functions in construction, they are not designed for measuring angles.

In summary, the theodolite is the most accurate and versatile instrument for measuring vertical angles, which is why it is the correct choice.