Date:
Chapter 3.5: Proving Lines Parallel
Objective -
Do Now: Pg. 205 #67, 70-73
Converse of Corresponding Angles Postulate:
Alternate Exterior Angle Converse:
Consecutive Interior Angle Converse:
Alternate Interior Angle Converse:
Perpendicular Transversal Converse:
Example 1: Identify Parallel Lines
A. Given 1  3, is it possible to prove that any of the
lines shown are parallel? If so, state the postulate or
theorem that justifies your answer.
B. Given m1 = 103 and m4 = 100, is it possible to prove that any of the lines
shown are parallel? If so, state the postulate or theorem that justifies your
answer.
A. Given 1  5, is it possible to prove that any of the lines shown
are parallel?
B. Given m4 = 105 and m5 = 70, is it possible to prove that any
of the lines shown are parallel?
Example 2: Use Angle Relationships
A. Find mZYN so that
||
. Show your work.
B. Find x so that GH || RS
GAMES In the game Tic-Tac-Toe, four lines intersect to form a square with four right
angles in the middle of the grid. Is it possible to prove any of the lines parallel or
perpendicular?
Write a proof for the following statement:
If m3  3x  5 and m5  5x  25 , find the value of x
to prove that line m and line n are parallel.
Given:
Prove:
Statements
Reasons