## Angles and Algebra

### Johnny WolfeSanta Rosa District Schools

#### Description

This lesson covers angle measure for triangles and complementary/supplementary angles.

#### Objectives

Understands and explains the effects of addition, subtraction, multiplication and division on real numbers, including square roots, exponents, and appropriate inverse relationships.

Uses properties and relationships of geometric shapes to construct formal and informal proofs.

#### Materials

-Overhead transparencies (if examples are to be worked on overhead) for Angles and Algebra (See Associated File)
-Marking pens (for overhead)
-Angles and Algebra Examples (See Associated File)
-Angles and Algebra Worksheet (See Associated File)
-Angles and Algebra Checklist (See Associated File)

#### Preparations

1. Prepare transparencies (if teacher uses overhead for examples) for Angles and Algebra Examples. (See Associated File)
2. Have marking pens (for overhead).
3. Have Angles and Algebra Examples (See Associated File) prepared and ready to demonstrate to students.
4. Have enough copies of Angles and Algebra Worksheet (See Associated File) for each student.
5. Have enough copies of Angles and Algebra Checklist (See Associated File) for each student.

#### Procedures

Prior Knowledge: Students should be familiar with basic operation skills such as addition, subtraction, multiplication, division, exponents, fractions, decimals and solving equations.
Note: This lesson does not address square roots, exponents, and appropriate inverse relationships nor does it address formal proofs.

1. Describe to students how to measure angles. (See #1 on Angles and Algebra Examples) Answer student questions and comments.

2. Ask the students to find the degree measure of ABC and CBD. Then have the students to find the sum of ABC and CBD. Go over the definition of supplementary angles. (See #2 on Angles and Algebra Examples) Answer student questions and comments.

3. Review with students how to name angles. (See #3 on Angles and Algebra Examples) Answer student questions and comments.

4. Work #4 example from Angles and Algebra Examples. (See Associated File) Answer student questions and comments.

5. Go over definition of complementary angles. (See #5 on Angles and Algebra Examples) Answer student questions and comments.

6. Work #6 example from Angles and Algebra Examples. (See Associated File) Answer student questions and comments.

7. Work #7 example from Angles and Algebra Examples. (See Associated File) Answer student questions and comments.

8. Work #8 example from Angles and Algebra Examples. (See Associated File) Answer student questions and comments.

9. Have students do the Thought Provoker. (See #9 on Angles and Algebra Examples) Make sure the students understand that the sum of the angles of a triangle equal 180 degrees. Answer student questions and comments.

10. Work #10 example from Angles and Algebra Examples. (See Associated File) Answer student questions and comments.

11. Work #11 example from Angles and Algebra Examples. (See Associated File) Answer student questions and comments.

12. Distribute the Angles and Algebra Worksheet. (See Associated File)

13. Distribute the Angles and Algebra Checklist. (See Associated File) Describe what constitutes an A, B, C, D, and F in the Checklist.

14. The students write their responses on the worksheet.

15. The teacher moves from student to student observing their work and lending assistance.

#### Assessments

Student worksheets are taken up and scored according to the Angles and Algebra Worksheet Key and Checklist. (See Associated File) These scores may be placed in the grade book.

#### Extensions

Have students determine the degrees in a pentagon by taking one of the vertices and dividing the figure into triangles. Have the students do this with other polygons as well.

#### Web Links

Web supplement for Angles and Algebra
Angles

Web supplement for Angles and Algebra
Triangle Geometry

#### Attached Files

This file contains the Angles and Algebra Examples, Worksheet, Worksheet Key, and Checklist.     File Extension: pdf