Lesson 3-5 Proving Lines Parallel

Ohio Content Standards:

Recognize and apply angle relationships in situations involving intersecting lines, perpendicular lines and parallel lines.

Ohio Content Standards: Solve and graph linear equations and inequalities.

Ohio Content Standards: Write and use equivalent forms of equations and inequalities in problem situations.

Ohio Content Standards: Describe and interpret rates of change from graphical and numerical data.

Ohio Content Standards: Recognize and explain that the slopes of parallel lines are equal and the slopes of perpendicular lines are negative reciprocals.

Postulate 3.4

If corresponding angles are congruent, then lines are parallel.

Postulate 3.5

If given a line and a point not on the line, then there exists exactly one line through the point that is parallel to the given line.

Theorem 3.5

If alternate exterior angles are congruent, then lines are parallel.

Theorem 3.6

If consecutive interior angles are supplementary, then lines are parallel.

Theorem 3.7

If alternate interior angles are congruent, then lines are parallel.

Theorem 3.8

If two lines are perpendicular to the same line, then lines are parallel.

Determine which lines, if any, are parallel.

P 100° 77° 103° R Q b a

P N M Z Y X Q W (11x - 25)° (7x + 35)°

Assignment: Pgs evens, evens