Download Theorem 3.9

Geometry 3.6
Big Idea: Prove
Theorems About
Perpendicular
Lines
Theorem 3.8
If two lines intersect to form a linear pair
of congruent angles, then the lines are ┴
.
Theorem 3.9
If two lines are perpendicular, then
they intersect to form 4 right angles .
In the diagram, AB ^ BC. What can
you conclude about Ð1and Ð2?
A
1
D
B
2
C
Theorem 3.10
If 2 sides of 2 adjacent acute angles
are ┴ , then the angles are
complementary.
In the diagram, AB ^ BC. Find the value
of x.
51
3x
Theorem 3.11
Perpendicular Transversal
Theorem
If a transversal is ┴ to one of 2
parallel lines, then it is ┴ to the other
line.
Theorem 3.12
Lines ┴ to a Transversal Theorem
In a plane, if 2 lines are ┴
to the same line, then they are parallel
to each other.
Distance from a Line
The shortest distance from a point to
a line is the length of a ┴ segment
from the point to the line.
Distance from a Line
The distance between any two ║
lines is the length of any ┴
segment joining the 2 lines.