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Chapter 1-4 (Measure and Classify Angles). What is an angle?. Two different rays with the same endpoint. Rays are the sides , endpoint is the vertex . Named with 3 points or by the vertex. sides. vertex. Chapter 1-4 (Measure and Classify Angles). Example.
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Chapter 1-4 (Measure and Classify Angles) • What is an angle? • Two different rays with the same endpoint. • Rays are the sides, endpoint is the vertex. • Named with 3 points or by the vertex. sides vertex
Chapter 1-4 (Measure and Classify Angles) • Example • Name the angles you see in the diagram C D A E
Chapter 1-4 (Measure and Classify Angles) • Measuring angles with a protractor • Different types of angles: • Write either <ABC is 32º or m<ABC=32º • Acute (less than 90º) • Obtuse (more than 90º • Right angle (exactly 90º) • Straight (180º)
Chapter 1-4 (Measure and Classify Angles) • Example • Postulate 4: Angle Addition • Page 25 in textbook • If P is in the interior of <RST, then the measure of <RST is equal to the sum of the measures of <RSP and <PST
Chapter 1-4 (Measure and Classify Angles) • Example • Given the m<GFJ=155º, find m<GFH and m<HFJ
Chapter 1-4 (Measure and Classify Angles) • Example • Given that <VRS is a right angle, find m<VRT and m<TRS
Chapter 1-4 (Measure and Classify Angles) • Congruent angles • 2 angles are congruent if they have the same measure (curved line) • <A <B A B
Chapter 1-4 (Measure and Classify Angles) • Example • Identify all pairs of congruent angles • If m<P=120º, what is m<N?
Chapter 1-4 (Measure and Classify Angles) • Angle Bisector • A ray that divides an angle into 2 angles that are congruent. • WY bisects <XWZ