# Linear Functions - Parallel and Perpendicular Lines

## introduction

Mobile Devices:

Tablets and smartphones can access the Parallel and Perpendicular Lines Animations on YouTube.

Workbook:

Download and print the Parallel and Perpendicular Lines Workbook.

Interactive Graphs:

All of the Parallel and Perpendicular Lines Graphs are interactive on Desmos.

Lesson Transcript:

All of the Parallel and Perpendicular Lines Notes are available as a video transcript.

Practice Exam:

Download and print the Unit Five Practice Exam.

Topics Covered:

- Determining if two lines are parallel, perpendicular, or neither.
- Using parallel and perpendicular slopes to solve for an unknown.
- Multi-step problems involving parallel and perpendicular lines.
- Problem solving (circle geometry)

Curriculum Connection: Relations & Functions 3.8, 7.4

Videos: Desktop computers and laptops require Adobe Flash Player and the printable notes require Adobe Reader. Smartphones and tablets will not be able access the Flash content on this page (resulting in empty space below). Use the YouTube alternative.

# Interactive

## parallel and perpendicular lines

### 2 Apps

App 1 - Slopes of Parallel and Perpendicular Lines: In this app, two line segments may be manipulated to find where they are parallel and perpendicular.

Teaching Tip: Click the "show second line" button to bring in the second line segment. Drag the endpoints to reposition the lines. When you are satisfied with the two lines, have students calculate the slope of each line using the endpoints displayed. When students complete their work, click the "show slopes" button so they can check their work. The small rectangular window in the lower right will show a green icon if the lines are perpendicular, a purple icon if the lines are parallel, and nothing if the lines are neither. (Note that the parallel/perpendicular status will updated when you release the mouse button after dragging an endpoint).

App 2 - Finding Parallel and Perpendicular Lines: In this app, a line segment and a point are given. Manipulate the line as required and position the point where it is needed. The equations of the parallel and perpendicular lines will be displayed in the panel.

Teaching Tip: A common question type in Math 10C goes like: "Given the equation y = 3x + 5, find the slope-intercept equation of a parallel line passing through (-2, -7)". This app is designed to help students visualize a question like this one. Start by positioning the endpoints of the line segment so it represents y = 3x + 5. Next, position the point at (-2, -7). To show the parallel line, click the parallel icon. To show the parallel equation, click the f(x) button.