Types of Angles: Angles are classified by size—acute ($<$90°), right (90°), obtuse (90°–180°), straight (180°), reflex (180°–360°), and full angle (360°).
Measuring Angles with a Protractor: Align the protractor’s centre with the vertex and the zero line with one arm. Read where the other arm crosses the scale; use the smaller number for acute angles and the larger for obtuse angles.
Constructing Angles Over 180°: For angles like 210°, draw the smaller internal angle (e.g., 150°), with the area outside forming the desired angle.