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Polygon 3
Activities

Lines in the Plane

Author
Texas Instruments
Alignment
Standards Alignment
Textbook Alignment
Subject Area
Math: Geometry: Points, Lines and Angles
Level
6-8
9-12
Activity Time
60 Minutes
Software
TI Connect™
TI Calculator
TI-84 series
Applications
Other Materials
    The following equipment is required for this activity:
  • TI-Presenter™

  • LCD Projector
  • Two screens
Resource Types
Lessons
Report an Issue

Lines in the Plane

Activity Overview

In this activity, students create a slope triangle and understand the concepts of slope and the equation of lines. They realize that slope is constant at all points along a fixed line. They also explore the slopes of parallel and perpendicular lines.

Before the Activity

Install the Cabri™: Jr. App on the students' graphing calculators using one of these two methods:

  • TI-Connect™,  a TI Connectivity Cable, and the Unit-to-Unit Link Cable
  • TI-Navigator™  "send to class" feature
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 1 - 7 from the attached PDF file for your class
    • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Draw a horizontal segment and construct a point on the y-axis
  • With the length of the segment as radius, draw a circle with the point as the center
  • Enlarge the circle so that the point in the first quadrant is in the upper right corner of the screen
  • Construct a point on the circle in the first quadrant and draw a line connecting it to the center
  • Hide the circle and the segment, and construct 2 points, A and C, on the line
  • Draw a perpendicular from C to the X-axis, and a perpendicular from A to the Y-axis
  • Label the intersection of the perpendiculars as B
  • Hide the perpendicular lines, draw segments AB and BC, measure their lengths, and compute the ratio BC/AB
  • Drag A or C along the line and observe the variation in the value of the ratio
  • Display the equation of the line and its slope
  • Rotate the line around the y-intercept and examine the relationship between the slope and the equation
  • Observe the changes in the equation as the y-intercept is changed
  • Explore the slopes of parallel and perpendicular lines and determine the products of the slopes of perpendicular lines
    • After the Activity

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary
    • icon-download-lm
    Download Files
    Before the Activity Files
    Teacher Notes PDF
    Author
    Texas Instruments
    Alignment
    Standards Alignment
    Textbook Alignment
    Subject Area
    Math: Geometry: Points, Lines and Angles
    Level
    6-8
    9-12
    Activity Time
    60 Minutes
    Software
    TI Connect™
    TI Calculator
    TI-84 series
    Applications
    Other Materials
      The following equipment is required for this activity:
    • TI-Presenter™

    • LCD Projector
    • Two screens
    Resource Types
    Lessons
    Report an Issue
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