Math Planet
Math Planet: Parallel and Perpendicular Lines
Provides examples and a video lesson that illustrates parallel and perpendicular lines.
Khan Academy
Khan Academy: Identify Parallel and Perpendicular Lines
Recognize parallel and perpendicular lines in geometric figures and pictures. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Draw Parallel and Perpendicular Lines
Practice drawing parallel and perpendicular lines, line segments, and ray. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Illustrative Mathematics
Illustrative Mathematics: G C, G Co Tangent Lines and the Radius of a Circle
In this task, students are shown a circle with center O and point P on the circle. L is a line that is a tangent to the circle at P. They must show that line OP is perpendicular to line L. Aligns with G-C.A.2, G-CO.A, and G-CO.C.9.
Illustrative Mathematics
Illustrative Mathematics: G Co Defining Perpendicular Lines
Three students have proposed three ways to describe when two lines are perpendicular. Students are asked to analyze their statements. Aligns with G-CO.A.1.
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.
Illustrative Mathematics
Illustrative Mathematics: G Srt Shortest Line Segment From a Point P to a Line L
In this task, students develop an understanding that the shortest path from a point to a line always meets the line at a right angle. Aligns with G-SRT.C.8.
Illustrative Mathematics
Illustrative Mathematics: G Gpe When Are Two Lines Perpendicular?
The goal of this task is to examine when two lines in the plane are perpendicular in terms of their slopes. Aligns with HSG-GPE.B.5.
BBC
Bbc: Bitesize: Rectilinear Shapes
Find the gradient, equations and intersections of medians, altitudes and perpendicular bisectors using our knowledge of the mid-point as well as parallel and perpendicular lines.
Math Open Reference
Math Open Reference: Points and Lines
A complete reference guide to points, lines, and planes. It provides definitions and interactive activities that enhance further explanation.
CK-12 Foundation
Ck 12: Elem Math: Determining Whether Lines Are Perpendicular
[Free Registration/Login may be required to access all resource tools.] Students watch two videos and attempt practice problems on how to determine if two lines are perpendicular.
CK-12 Foundation
Ck 12: Algebra: Families of Lines
[Free Registration/Login may be required to access all resource tools.] Find the equation of a line that is parallel or perpendicular 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.] 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: 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.
Alabama Learning Exchange
Alex: Geometric Man
The students will explore angles, rays, line segments, perpendicular lines, parallel lines, and two-dimensional figures through the use of the book Shape Up! Fun With Triangles and Other Polygons by David A. Adler. They will also...
Alabama Learning Exchange
Alex: Plane Ole Plottinghttp
Students will develop an understanding of the Cartesian plane through questioning and reasoning. Students will also gain a deeper understanding of the four quadrants within the coordinate system.
CK-12 Foundation
Ck 12: Algebra: Determining the Equation of a Line
This comprehensive study guide highlights the main terms and formulas needed to determine the equation of a line. Examples are included.
CK-12 Foundation
Ck 12: Algebra: Lines in the Coordinate Plane Study Guide
This comprehensive study guide highlights the main terms and formulas needed to review lines in the coordinate plane. Examples are included.
CK-12 Foundation
Ck 12: Geometry: Angles and Transversals Study Guide
This study guide on angles and transversals covers key terms, angle types formed by transversals, postulates and theorems about transversals, and how to prove if lines are parallel or perpendicular. It is available for download with free...
CK-12 Foundation
Ck 12: Geometry: Lines and Angles Study Guide
This study guide on lines and angles covers key terminology; line notation; parallel, perpendicular, and skew lines; and postulates and theorems about lines. It is available for download with free registration.
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: Parallel & 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.
Geometry Help
Geometry Help: What Are Perpendicular Lines in Geometry?
Explains the basic concept of perpendicular lines with step-by-step instructions and methods for solving specific problems on your own relating to this topic.