Interactivate

Angles
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Abstract

The following lesson is designed to introduce students to acute, obtuse, and right angles. It is also designed to introduce students to vertical angles, adjacent angles, alternate interior angles, alternate exterior angles, same-side interior angles, same-side exterior angles, and corresponding angles.

Objectives

Upon completion of this lesson, students will:

  • identify angles as acute, obtuse or right
  • identify pairs of angles with special relationships: vertical angles, adjacent angles, alternate interior angles, alternate exterior angles, same-side interior angles, same-side exterior angles, and corresponding angles

Standards Addressed:

Textbooks Aligned:

Student Prerequisites

  • Technological: Students must be able to:
    • perform basic mouse manipulations such as point, click and drag
    • use a browser for experimenting with the activities

Teacher Preparation

  • access to a browser
  • pencil and paper
  • copies of supplemental materials for the activities:

Key Terms

acute angleAn angle whose measure is less than 90 degrees
adjacent anglesTwo angles that share a ray, thereby being directly next to each other
alternate exterior anglesAngles located outside a set of parallel lines and on opposite sides of the transversal
alternate interior anglesAngles located inside a set of parallel lines and on opposite sides of the transversal
corresponding anglesTwo angles in the same relative position on two lines when those lines are cut by a transversal
obtuse angleAn angle whose measure is greater than 90 degrees
right angleAn angle of 90 degrees
same side exterior anglesAngles located outside a set of parallel lines and on the same side of the transversal
same side interior anglesAngles located inside a set of parallel lines and on the same side of the transversal
vertical anglesThe two nonadjacent angles formed when two straight lines intersect

Lesson Outline

  1. Focus and Review

    Remind students what has been learned in previous lessons that will be pertinent to this lesson and/or have them begin to think about the words and ideas of this lesson. Discuss key words that they're already familiar with:

    • acute angle
    • obtuse angle
    • right angle

  2. Objectives

    Let the students know what it is they will be doing and learning today. Say something like this:

    • Today, class, we are going to learn about different types of angles and the ways groups of angles can be related to each other.
    • We are going to use the computers to learn about angles, but please do not turn your computers on until I ask you to. I want to show you a little about this activity first.

  3. Teacher Input

    Open your browser to the Angles activity in order to demonstrate it to the students. Ask students guided questions:

    • Which angles look similar?
    • Which angles look different?
    • How are the angles related?

    Lead the students through the discussion about angles.

  4. Guided Practice

    Explain to the students how to do the assignment. You should model or demonstrate it for the students, especially if they are not familiar with how to use our computer applets.

    • Open your browser to the Angles activity in order to demonstrate it to the students.
    • Show students where they select their answers for the specified angle by clicking on the pop-down menu and scrolling to the correct answer.
    • Click on the "check answer" button to see if your choices are correct.
    • When the correct answers are found, click the "new angles" button to change to a new set of angles.

  5. Independent Practice

    • Allow the students to work on their own to complete the Angles Worksheet, using the applet projected on the wall. Monitor the room for questions and to be sure that the students are on the correct web site.
    • Have students work on a computer, if it's available, to complete a self-quiz using the applet.

  6. Closure

    You may wish to bring the class back together for a discussion of the findings. Discuss with students how they went about answering questions and how they knew when they were correct. Once the students have been allowed to share what they found, summarize the results of the lesson.

Alternate Outline

This lesson can be rearranged in several ways if you have limited computer access:

Suggested Follow-Up
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