Which tool is commonly used to mark and measure right angles in carpentry?

• A. Speed Square
• B. Measuring Tape
• C. Open End Wrench
• D. Osmosis

Answer: (A)

Marking and checking right angles efficiently in carpentry is best done with a speed square. This triangular tool is built to act as both a straightedge and a square, giving you a true 90-degree reference along the edge of your workpiece. It also provides a 45-degree reference, which is handy for marking miters and angled cuts without guessing. Because it sits flat against the edge and includes these built-in angle guides, you can quickly scribe perpendicular lines, verify squareness on frames and joints, and set up consistent repeatable marks with a single tool.

Other items don’t fit this specific purpose. A measuring tape is for length, not angle layout. An open-end wrench is used for turning fasteners. Osmosis is a biological process unrelated to tools or carpentry.