www.purplemath.com/modules/slope3.htm

Parallel lines and their slopes are easy. Since slope is a measure of the angle of a line from the horizontal, and since parallel lines must have the same angle, then parallel lines have the same slope — and lines with the same slope are parallel. Perpendicular lines are a bit more complicated. If you visualize a line with positive slope (so ...

www.mathsisfun.com/algebra/line-parallel-perpendicular

Two lines are Perpendicular when they meet at a right angle (90°). To find a perpendicular slope: When one line has a slope of m, a perpendicular line has a slope of −1 m. In other words the negative reciprocal. Find the equation of the line that is. perpendicular to y = −4x + 10. and passes though the point (7,2)

www.emathhelp.net/calculators/algebra-1/parallel-and-perpendicular-line-calculator

The calculator will find the equation of the parallel/perpendicular line to the given line, passing through the given point, with steps shown. For drawing lines, use the graphing calculator. In general, you can skip the multiplication sign, so 5 x is equivalent to 5 ⋅ x. In general, you can skip parentheses, but be very careful: e^3x is e 3 x ...

www.mathwarehouse.com/algebra/linear_equation/parallel-perpendicular-lines.php

Parallel lines have the same slope and will never intersect. Parallel lines continue, literally, forever without touching (assuming that these lines are on the same plane). On the other hand, the slope of perpendicular lines are the negative reciprocals of each other, and a pair of these lines intersects at 90 degrees.

www.algebralab.org/lessons/lesson.aspx?file=Geometry_CoordParallelPerpendicular.xml

Therefore the slope is and the slope of a perpendicular is . A line with this slope and containing the point (-1, -1) will have an equation given by . Important facts: If two line segments are parallel, their slopes are the same. If two line segments are perpendicular, their slopes are negative reciprocals.

mashupmath.com/blog/parallel-slope-perpendicular-slope-lines

Parallel Slope and Perpendicular Slope Before you learn how to graph parallel and perpendicular lines, let’s quickly review some important information: Parallel Lines. Never intersect. Have the SAME SLOPE (m) For example, observe the purple line and the green line in Figure 1 below. These lines are parallel and have the same slope of m=3/5.

study.com/academy/lesson/perpendicular-slope-definition-examples.html

Now that we recall what perpendicular lines are, there's just one more thing to review before getting to the relationship of the slopes of these lines, and that is the slope of a line.

www.wtamu.edu/academic/anns/mps/math/mathlab/col_algebra/col_alg_tut28_parpen.htm

Find the slope of a line that is parallel to a given line. Find the slope of a line that is perpendicular to a given line. This tutorial looks at the relationship between the slopes of parallel lines as well as perpendicular lines. Once again we are going to be using material from our math past to help find the new concept.

www.purplemath.com/modules/slope2.htm

The second line's equation was y = –2 x + 3, and the line's slope was m = –2.. In both cases, the number multiplied on the variable x was also the value of the slope for that line. This relationship always holds true: If the line's equation is in the form "y=", then the number multiplied on x is the value of the slope m.

virtualnerd.com/geometry/parallel-perpendicular-lines/slopes

Perpendicular lines intersect at right angles to one another. To figure out if two equations are perpendicular, take a look at their slopes. The slopes of perpendicular lines are opposite reciprocals of each other. Their product is -1! Watch this tutorial and see how to determine if two equations are perpendicular.