## How Do You Pay a Complement to an Angle?

### Johnny WolfeSanta Rosa District Schools

#### Description

Complementary angles are two angles that form a right angle (90 degrees). Students practice finding the complement of an angle.

#### Objectives

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

#### Materials

-Overhead transparencies (if examples are to be worked on overhead) for How Do You Pay a Complement to an Angle? (See attached file.)
-How Do You Pay a Complement to an Angle? Examples (See attached file.)
-How Do You Pay a Complement to an Angle? Worksheet (See attached file.)

#### Preparations

1. Prepare transparencies (if teacher uses overhead for examples) for How Do You Pay a Complement to an Angle? (See attached file.)
3. Have How Do You Pay a Complement to an Angle? prepared and ready to demonstrate to students. (See attached file.)
4. Have enough copies of How Do You Pay a Complement to an Angle Activity Sheet for each student. (See attached file.)

#### Procedures

Prior Knowledge: Students should be familiar with basic operation skills, such as addition, subtraction, multiplication, division, exponents, fractions, decimals, solving equations, and working with angles.

1. Get students' attention by making the statement: Today is a special day, we are going to pay a [complement] to an angle.

2. Go over Discussion Question #1 on How Do You Pay a Complement to an Angle? (See attached file.) Have students develop a definition for a complementary angle.

3. Go over Definition of Complementary Angles. (See attached file: How Do You Pay a Complement to an Angle?)

4. Work example #1 from How Do You Pay a Complement to an Angle? (See attached file.) Answer student questions and comments.

5. Go over Complementary Angle Theorem. (See attached file: How Do You Pay a Complement to an Angle?)

6. Work example #2 from How Do You Pay a Complement to an Angle? (See attached file.) Answer student questions and comments.

7. Work example #3 from How Do You Pay a Complement to an Angle? (See attached file.) Emphasize the changing of units. Answer student questions and comments.

8. Work example #4 from How Do You Pay a Complement to an Angle? (See attached file.) Answer student questions and comments.

9. Work Example #5 from How Do You Pay a Complement to an Angle? (See attached file.) Answer student questions and comments.

10. Hand out the How Do You Pay a Complement to an Angle? (See attached file.)

11. Hand out the rubric for How Do You Pay a Complement to an Angle? (See attached file.) Describe what constitutes a 1, 2, and 3 in the rubric.

12. The students will write their responses to the activity sheet questions in their math journals.

13. Move from student to student observing the students' work and lending assistance.

14. Collect work.

#### Assessments

Observe students as they complete the activity sheet: How Do You Pay a Complement to an Angle? (See Associated File.) Use the key for How Do You Pay a Complement to an Angle? Use the percent of answers correct and your district's grading scale to determine mastery. Students who do not demonstrate understanding need additional feedback and practice.

#### Extensions

Have students divide into pairs. One student will draw an angle and place a measurement inside. The second student will find the complement of the angle.