Download 3.6.1 prove theorems about perpendicular lines

Chapter 3
Parallel and Perpendicular Lines
3.6.1 PROVE THEOREMS ABOUT PERPENDICULAR LINES
SWBAT:
1) Prove and use theorems about perpendiculars to solve problems.
2) Prove lines perpendicular.
3) Find angle measure using theorems about perpendiculars.
Perpendicular Line Theorems
 If two lines intersect to from a linear pair of
congruent angles, then the two lines are
perpendicular
 What does linear pair mean?
 If they are congruent what measure must they be?
 Ex. If 1  2 then g  h
h
2
1
g
Perpendicular Line Theorems
 If two lines are perpendicular, then they intersect
to form four right angles.
 If g  h then 1, 2, 3, and 4 are right angles
g
1
2
4
3
h
Perpendicular Line Theorems
 If two sides of two adjacent acute angles are
perpendicular, then the angles are complementary.
 If BA  BC, then 1 and 2 are complementary
A
1
2
B
C
Check Point 1)
 Given that ABC  ABD what can you conclude
about 3 and 4?
A
3
4
C
B
D
Homework
 P. 194
 2 – 7, 15 – 17, 26, 35 – 38, 41