Transcript 3.4 parallel Lines and the Triangle Angle

3.4 parallel Lines and the Triangle
Angle-Sum Theorem
12.0 Students find and use measures of interior and exterior
angles of triangles to classify figures and solve problems
13.0 Students prove relationships between angles in
polygons by using properties of complementary,
supplementary, vertical, and exterior angles
Triangle Angle-Sum Theorem
• The sum of the measures of the angles of a
triangle is 180
Example #1
Example #2
Example #3
Classifying Different Triangles
Vocabulary
• Exterior angle of a polygon – an angle formed
by an side and an extension of an adjacent
side
Vocabulary
• Remote interior angle – two nonadjacent
interior angles
Example #1
X
90
123°
Example #2
Z
57°
57°
Example #3
20°
43°
X
Y
35°
Z
Assignment
• Pg 150 #1-9, 20, 24, 26