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What do you know about parallel lines? What do you know about perpendicular lines?. How do you think you could prove 2 lines are parallel? How do you think you could prove 2 lines are perpendicular?. Bellwork 12-12-07. Parallel and Perpendicular Lines. Lesson 5-6 P. 292. Parallel Lines.
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What do you know about parallel lines? What do you know about perpendicular lines? How do you think you could prove 2 lines are parallel? How do you think you could prove 2 lines are perpendicular? Bellwork 12-12-07
Parallel and Perpendicular Lines Lesson 5-6 P. 292
Parallel Lines • 2 lines that never intersect • 2 lines are parallel when they have the same slope (regardless of their other points, i.e. y-intercept) • All vertical lines are parallel
Writing an equation for a Parallel line • You can write an equation for a parallel line if you know the slope and a point on the line. • You may need to find the slope • Use the SAME slope • Substitute the point and slope into point slope form.
Perpendicular Lines • Lines that intersect at right angles (90 degrees) • 2 non-vertical lines are perpendicular if the product of their slopes is -1. • If the slopes are multiplied together and you get -1 as an answer. • Their slopes are opposite reciprocals.
Writing an equation perpendicular to a given Equation • Figure what the opposite reciprocal of the given slope is • Substitute the slope and point into point slope form.