1. 1.5 Parallel and Perpendicular Lines on the Coordinate Plane
9/27/14
H.W. Flipbook 1.5 and Crossword 1.5

2. Key Terms
Slope Formula – The formula that will give you the slope of the line: y2 – y1
x2 – x1
Point Slope Formula – The point-slope form of a linear equation is y – y1 = m( x – x1) where “m” is slope and (x1 y1) is a point on the line.
Slope – A measure of the steepness of a line. If (x1 y1) and (x2 y2) are any two points on the line, the slope of the line, represented by “m”, is m= y2 – y1

3. Key Terms
Y-Intercept – The “y” coordinate of the point where a graph intersects the “y” axis.
Parallel – Lines in the same plane that do not intersect.
Perpendicular – Intersecting to form 90 degree angles.

4. Key Terms
Midpoint Formula – It can be used to calculate the midpoint between two points. The formula is (x1 + x2 , y1 + y2)
Rise to Run – The slope of the line (m) is the ration of rise to run for any two points on the line. The rise is represented by the “y” values and the run is represented by the “x” values.

5. Parallel Lines
Two different non vertical lines are parallel if and only if they have the same slope.
IE y = 4x and y = 4x - 5
All different vertical lines are parallel.
IE x = 2 and x = 4

6. Perpendicular Lines Two intersecting lines that form a 90 degree angle
Two non vertical lines are perpendicular if and only if the product of their slope is – 1.
IE y = -2/3x and y = 3/2x – 2
Vertical Lines are perpendicular to horizontal lines.
IE y = 3 and x = 2