Angle measurement refers to the process of determining the size of an angle, which is formed by two rays that share a common endpoint called the vertex. Angles are typically measured in degrees (°) or radians. A full circle contains 360 degrees, while a complete revolution in radians is equivalent to 2\pi radians. To measure angles, various tools can be used, such as a protractor or a digital angle finder. Angles can be classified into different types based on their measurements: acute angles (less than 90°), right angles (exactly 90°), obtuse angles (greater than 90° but less than 180°), and straight angles (exactly 180°).