How do you determine 45 and 90-degree angles accurately?

The combination square is specifically designed to accurately measure and mark angles, including both 45 and 90 degrees. It typically features a ruler with a movable arm that can be set at various angles, making it ideal for transfer and checking of these specific measurements.

Its versatility allows it to be used for marking, measuring, and finding square edges, which is crucial in tasks like woodworking and metalworking. For example, you can use the built-in 45-degree angle on the head of the combination square to quickly set or verify a 45-degree angle by aligning the blade with the edge of the material.

In contrast, a protractor is primarily used for measuring angles rather than marking them and, while it can measure 45 and 90 degrees, it is less practical for direct application in constructing or verifying right angles and miter cuts. A carpenter's square, while effective for checking 90-degree angles, does not conveniently address 45-degree angles in a single tool format. A bevel gauge, on the other hand, is used for transferring and replicating angles but does not provide a built-in reference for specific angles like 45 or 90 degrees, making the combination square the most effective choice for determining these angles accurately.