Transcript Lesson 4-2 Angles of Triangles

Lesson 4-2
Angles of Triangles
Concept 1
Concept 2
Example
1 Angle-Sum
Use the Triangle
Theorem
SOFTBALL The diagram
shows the path of the
softball in a drill developed
by four players. Find the
measure of each numbered
angle.
Example
1 Angle-Sum
Use the Triangle
Theorem
Example 1
Find the measure of 3.
A. 95
B. 75
C. 57
D. 85
Concept 3
Example
2 Angle Theorem
Use the Exterior
GARDENING Find the measure
of FLW in the fenced flower
garden shown.
Example 2
The piece of quilt fabric is in the shape of a right
triangle. Find the measure of ACD.
A. 30
B. 40
C. 50
D. 130
Concept 5
Example 3
Find Angle Measures in Right Triangles
Find the measure of
each numbered angle.
Example 3
Find Angle Measures in Right Triangles
Example 3
Find m3.
A. 50
B. 45
C. 85
D. 130
Vocabulary
• Auxiliary line-Extra line or segment drawn in a
figure to help analyze geometric relationships.
• Exterior angle-Formed by one side of the triangle
and the extension of an adjacent side.
• Remote interior angles- Each exterior angle of a
triangle that are not adjacent to the exterior angle.
• Flow proof-Use statements written in boxes and
arrows to show the logical progression of an
agrument.