1. Geometry 1.4 SWLT Measure and Classify Angles

2. Classifying Angles Acute Angles: 0  < m  A < 90  Right Angles m  A = 90  A A

3. Classifying Angles (Con’t) Obtuse Angles 90  < m  A < 180  Straight Angle m  A = 180  A A

4. Angle Addition Postulate If P is in the interior of  RST, then the m  RST is equal to the sum of the measures of  PST and  RSP P S R T

5. Applying the Angle Addition Postulate Given: m  GFJ = 155 , m  GFH = (4x + 4)  and m  HFJ = (4x – 1)  Find m  GFH & m  HFJ m  GFJ = m  GFH + m  HFJ 155  = (4x + 4)  + (4x – 1)  155 = 8x + 3 152 = 8x x = 19 m  GFH = (4(19) + 4)  = 80  m  HFJ = (4(19) – 1)  = 75  G F J H

6. Angle Bisectors Statement: If WY bisects  ZWX, then  XWY   ZWY Converse: If  XWY   ZWY, then WY bisects  ZWX X Y W Z

7. Using Angle Bisectors Given: KM bisects  LKN and m  LKM = 78° Find m  LKN Solution:  LKM ≅  MKN m  LKN = m  LKM + m  MKN m  LKN = 78° + 78° m  LKN = 156° L M K N