Angles #29 Acute angle (def)- angle less than 90° # 28 Right angle (def)- angle = 90° #30 Obtuse angle (def)- angle greater than 90° #31 Straight angle (def)- angle = 180° #26 Interior of angle #27 Exterior of angle

To Name an Angle- either use 3 letters or number it, never use only 1 letter. Name with vertex in the middle. A D or never vertex 1 2 B C Congruent angles- angles that have = measures. - measure of an angle

#33 Adjacent Angles (def)-2 coplanar angles that share a common ray #36 Linear Pair (def)-adjacent angles whose non-common sides form a line. (describes) #39 Linear Pair Theorem- If 2 angles form a linear pair, then they are supplementary.(Value)

#35 Vertical Angles(def)- 2 nonadjacent angles formed by intersecting lines (describes) 1 4 2 3 #42 Vertical Angles Theorem- If 2 angles are vertical, then they are congruent. (value)

#37 Complementary angles (def)- 2 angles whose sum is 90° or 50° 40°

#38 Supplementary angles(def) – 2 angles whose sum is 180° or 145° 35°

#34 Angle Bisector(def)- is a ray that divides the angle into 2 congruent angles. #32 Angle Addition Postulate- sum of the parts = whole