Parallel and Perpendicular Lines……
Slopes…… Parallel Lines: The slopes are EQUAL for parallel lines. Perpendicular Lines: The slopes are opposite reciprocals for perpendicular lines.
Example……If PARALLEL: PERPENDICULAR:
You Try....... If find the parallel and perpendicular slopes. Parallel: Perpendicular:
You Try…… If find the parallel and perpendicular slopes.
Answer……Remember Parallel: Perpendicular:
Example…… A. What is the slope of ? B. What is the parallel slope? C. What is the perpendicular slope? A. B. C.
Example…… Graph the line parallel to through (8,2).
Answer…..Parallel to
Graph …….
Example……. Graph the line perpendicular to through (3,2)
Answer…Perpendicular to
Graph……
Are the following lines parallel, perpendicular, or neither?.......... Answer: They have the same slope so they are parallel.
Parallel, Perpendicular, or Neither? The slopes are not the same so they are NOT parallel. The slopes are not opposite reciprocals so they are NOT perpendicular. They are neither.
Parallel, Perpendicular, or Neither?...... You must first change both into slope-intercept form. Now, you can compare their slopes.
They are not the same so they are NOT parallel. They are not opposite reciprocals so they are NOT perpendicular. They are neither.
Parallel, Perpendicular, or Neither?..... Change to slope-intercept form first. Compare their slopes.
The slopes are opposite reciprocals so they are perpendicular.
Assignment…… Worksheet