What tool is used to measure vertical angles, run straight lines, and determine if a wall is plumb?

• A. Carpenter's level.
• B. Tape measure.
• C. Chalk line.
• D. Square.

Answer: (A)

A carpenter's level is designed to check alignment relative to gravity, making it the tool for confirming vertical plumb and guiding straight lines. Its vertical vial shows when a surface is perfectly upright, so you can verify that a wall is truly plumb. You can also use the level along a straight edge to sight a straight line across a surface, which helps when running lines for framing or placement. The other tools have different primary roles: a tape measure for length, a chalk line for marking a line without confirming verticality, and a square for checking right angles. So the carpenter's level best fits measuring vertical orientation, aiding straight-line work, and ensuring walls stand plumb.