parallel, perpendicular, and oblique lines
DESCRIPTION
Parallel, Perpendicular, and Oblique Lines. Using Coordinate Geometry to Find and Compare t he Slopes of Lines. Parallel Lines. Two lines are Parallel if they lie in the same plane and do not intersect. Perpendicular Lines. Two lines are Perpendicular if they intersect at a right (90°). - PowerPoint PPT PresentationTRANSCRIPT
Parallel, Perpendicular, and Oblique Lines
Using Coordinate Geometry to Find and Compare the Slopes of Lines
Parallel Lines• Two lines are Parallel if they lie in the
same plane and do not intersect
Perpendicular LinesTwo lines are Perpendicular if they intersect at a right (90°)
Oblique LinesTwo lines are Oblique if they lie in the same plane but are neither Perpendicular nor Parallel
Skew LinesTwo lines are Skew if they do not lie in the same plane
SlopeRecall that slope = , so draw in a slope triangle to find the rise and run
8
6 4
3
𝑟𝑖𝑠𝑒𝑟𝑢𝑛=
86 =
43
l
Parallel LinesSince Parallel lines never intersect but lie in the same plane, they must have the same slope
3Slope of line l =
4
3
4
l m
Slope of line m =
Perpendicular LinesSince Perpendicular lines intersect at right angles, there slopes are opposite reciprocals
3
4
-3 4
l
n
Slope of line l =
Slope of line n =
Oblique LinesSince Oblique lines are neither parallel nor perpendicular, there slopes are not equal, nor opposite reciprocals
3
7
-3 4
l
q
Slope of line l =
Slope of line q =
ReviewParallel Lines Never intersect Same Slope
Perpendicular Lines Intersect at a Right Angle Opposite Reciprocal Slope
Oblique Lines intersect at a non-right angle Non-equal and non-opposite recriprocal slopes