6.4.2 I can describe figures by using the terms of geometry Vocabulary point line plane line segment ray Use the diagram to name the geometric figure. A. three points B. two lines U V W T S Use the diagram to give a possible name to the figure. A. three different line segments A B C B. three ways to name the line Lesson Quiz Use the diagram to name each geometric figure. Possible answer: A, 1. three points B, C 2. two lines Possible answer: AD, CE 3. a point shared by a line and Possible answer: F a ray 4. a plane Possible answer: plane AEC 6.4.2 I can name, measure, draw, and classify angles Vocabulary angle vertex acute angle right angle obtuse angle straight angle An acute angle measures greater than 0° and less than 90°. A right angle measures exactly 90°. Reading Math Right angles are usually marked with a symbol. An obtuse angle measures greater than 90° and less than 180°. A straight angle measures exactly 180°. Additional Example 3: Classifying Angles Classify each angle as acute, right, obtuse, or straight. A. The angle measures less than 90°, so it is an acute angle. B. The angle measures exactly 90°, so it is a right angle. Check It Out: Example 3 Classify each angle as acute, right, obtuse, or straight. A. The angle measures less than 90°, so it is an acute angle. B. The angle measures exactly 180°, so it is a straight angle.