Which tool is used to verify that a cabinet corner is square?

• A. Tape measure
• B. Carpenter's square
• C. Hammer
• D. Level

Answer: (B)

Ensuring a cabinet corner is square means the two meeting edges form a true 90-degree angle, which is essential for accurate assembly and door alignment. A carpenter's square is designed for this purpose; its 90-degree interior corner lets you place it in the cabinet corner and check both edges at once. If the square sits flush along both sides, the corner is square. If there’s a gap on one side, the angle isn’t right and needs adjustment. The other tools don’t verify the angle as directly: a tape measure handles length, a level checks level or plumb on surfaces but not the exact corner angle, and a hammer is for driving fasteners.