What tool is primarily used for measuring angles in carpentry?

In carpentry, the speed square is primarily used for measuring angles due to its triangular shape with a 90-degree angle and various degree markings along the edges, allowing for quick and accurate angle measurements. Its design makes it particularly convenient for marking roof rafters, squaring up cuts, and ensuring the accuracy of angles in various projects, particularly those involving framing.

While other tools listed, such as the protractor, measuring tape, and combination square, each serve specific purposes in measuring angles or lengths, the speed square stands out for its versatility and ease of use in the context of carpentry. The protractor is ideal for more precise angle measurements but is generally less feasible for tasks that require quick, repeatable angle checks. The measuring tape is essential for length measurements but does not inherently provide angle information. The combination square does offer both angle measurement and length functionality but is generally used for a different scope of work compared to the speed square's more task-oriented angle applications in carpentry.