CK-12 Foundation
Ck 12: Geometry: Perpendicular Lines in the Coordinate Plane
[Free Registration/Login may be required to access all resource tools.] This concept teaches students about perpendicular lines in the coordinate plane, and how to use slopes to determine whether or not two lines are perpendicular.
CK-12 Foundation
Ck 12: Algebra: Equations of Perpendicular Lines
[Free Registration/Login may be required to access all resource tools.] This lesson covers determining if two lines are parallel, perpendicular, or neither and finding the equation of perpendicular lines to a given line.
CK-12 Foundation
Ck 12: Algebra: Equations of Perpendicular Lines
[Free Registration/Login may be required to access all resource tools.] Learn how to recognize and write equations of perpendicular lines.
CK-12 Foundation
Ck 12: Algebra: Equations of Perpendicular Lines
[Free Registration/Login may be required to access all resource tools.] Learn how to recognize and write equations of perpendicular lines.
Math Planet
Math Planet: Parallel and Perpendicular Lines
Provides examples and a video lesson that illustrates parallel and perpendicular lines.
Khan Academy
Khan Academy: Parallel and Perpendicular Lines From Equation
Use your knowledge about the slopes of parallel and perpendicular lines to solve some problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Texas Instruments
Texas Instruments: Investigating the Slopes of Parallel and Perpendicular Lines
In this activity, students investigate how equations of parallel and perpendicular lines relate to each other. They use the drawing and measurement tools of Cabri Jr. to explore the slopes of lines. [Requires Adobe Reader.]
Oswego City School District
Regents Exam Prep Center: Parallel and Perpendicular Lines
This site displays formulas and examples, pertaining to slope, for parallel and perpendicular lines.
Texas Instruments
Texas Instruments: Investigating Parallel and Perpendicular Lines Using Cabri Jr
Students use Cabri Jr. App to investigate the slopes and equations of parallel and perpendicular lines.
Cool Math
Coolmath: Perpendicular Lines
This CoolMath Resource will help students determine if lines are perpendicular by finding the slope, using the point-slope formula, and graphing.
Khan Academy
Khan Academy: Write Equations of Parallel and Perpendicular Lines
Write the equation for a line that is a parallel or perpendicular to a line given in slope-intercept form and that goes through a specific point. Students receive immediate feedback and have the opportunity to try questions repeatedly,...
Khan Academy
Khan Academy: Parallel and Perpendicular Lines From Graph
Given points that two lines go through or the graph of each line, classify the lines as parallel, perpendicular, or neither. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or...
CK-12 Foundation
Ck 12: Geometry: Perpendicular Lines in the Coordinate Plane
[Free Registration/Login may be required to access all resource tools.] Use slopes to determine if two lines are perpendicular.
Illustrative Mathematics
Illustrative Mathematics: G Gpe, G Srt Slope Criterion for Perpendicular Lines
The goal of this task is to use similar triangles to establish the slope criterion for perpendicular lines. Aligns with HSG-GPE.B.5 and HSG-SRT.B.5.
Purple Math
Purplemath: Slope: Parallel and Perpendicular Lines
Describes and gives good examples relating to the slopes of parallel and perpendicular lines.
Texas Instruments
Texas Instruments: Explore Parallel and Perpendicular Lines
Students can use a graphing calculator to explore graphs of parallel and perpendicular lines. Students will find that parallel lines have the same slope and different y-intercepts and that the slopes of two perpendicular lines are...
Texas Instruments
Texas Instruments: Parallel and Perpendicular Lines on Ti Smartview
This is an introductory lesson on graphing parallel and perpendicular lines. The students will have a good visual on how these lines relate to each other. This also illustrates how to determine equations in slope-intercept form of a line...
CK-12 Foundation
Ck 12: Interactive Geometry: 10.4 Slope of Parallel and Perpendicular Lines
Understand how to find the slope of parallel and perpendicular lines.
Northeast Parallel Architectures Center, Syracuse University
Npac Reu Program: Parallel and Perpendicular Lines
Northeast Parallel Architecture Center, Syracuse University provides a brief definition of the slopes of parallel and perpendicular lines
CK-12 Foundation
Ck 12: Algebra: Comparing Equations of Parallel and Perpendicular Lines
[Free Registration/Login may be required to access all resource tools.] Use their slopes to determine if two lines are parallel or perpendicular.
Lawrence Hall of Science
The Math Page: Skill in Algebra: The Slope of a Straight Line
Here is a site that clearly and thoroughly explains many topics surrounding the slope of a line, including slope of horizontal, vertical, parallel, and perpendicular lines in addition to the formula and concept of slope. There are...
National Council of Teachers of Mathematics
The Math Forum: Lines and Slope: Chameleon Graphing
Join Joan the chameleon in an exploration of lines and slope. You'll be drawing lines, calculating slope, using equations and more!
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator: Parallel, Perpendicular, Slope, Transversal
Practice using your graphing calculator for drawing parallel lines, perpendicular lines, slope, and transversals. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly...
Texas Education Agency
Texas Gateway: Coordinate Geometry: Parallel and Perpendicular Lines
Given characteristics of two lines, such as slopes and equations, the student will determine whether the lines are parallel, perpendicular, or neither.