Measure and classify angles

Learning Objectives Define an angle and identify its parts (vertex, rays). Accurately measure angles in degrees using a protractor. Classify angles as acute, right, obtuse, or straight based on their measure. Draw an angle of a given measure using a protractor. Identify adjacent and vertical angles in a diagram. Determine the measure of an unknown angle using the properties of angles on a straight line and vertical angles. Have you ever wondered what makes the perfect slice of pizza or why a skateboard ramp is steep? 🍕 It's all about angles! In this tutorial, you'll learn what angles are, how to measure them using a tool called a protractor, and how to classify them into different types. Understanding angles is a key building block for geometry and helps us descr...

TermDefinitionExample AngleAn angle is formed by two rays that share a common endpoint.The corner of a square is an angle. The hands on a clock at 3:00 form an angle. VertexThe common endpoint where the two rays of an angle meet.The point in the very corner of a room where two walls and the floor meet is a vertex. Degree (°)The standard unit used to measure the size of an angle. A full circle has 360 degrees.A perfect corner, like in a square, measures 90 degrees, written as 90°. ProtractorA tool, usually a semi-circle, used for measuring or drawing angles in degrees.You would use a protractor to find out that the angle of a typical staircase is about 35°. Adjacent AnglesTwo angles that are next to each other. They share a common vertex and a common side, but do not overlap.If you cut a p...

Angle Classification Rules Acute: 0° < angle < 90° Right: angle = 90° Obtuse: 90° < angle < 180° Straight: angle = 180° Use these rules to classify an angle after you have measured it. Compare the angle's measure to 90° and 180° to determine its type. Angles on a Straight Line angle_1 + angle_2 = 180° If two or more adjacent angles form a straight line, their measures will always add up to 180°. Use this to find a missing angle on a line. Vertical Angles Rule Vertical angles are equal. When two lines intersect, the angles directly opposite each other are called vertical angles. They always have the same measure.