Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Rotation formalisms in three dimensions wikipedia , lookup
Line (geometry) wikipedia , lookup
Integer triangle wikipedia , lookup
History of trigonometry wikipedia , lookup
Pythagorean theorem wikipedia , lookup
Rational trigonometry wikipedia , lookup
Compass-and-straightedge construction wikipedia , lookup
Multilateration wikipedia , lookup
Trigonometric functions wikipedia , lookup
LESSON NO. 6 DATE: OCTOBER ,2007 COMPETENCIES D1. 3 Angles of a Parallelogram I. Objectives 1 To derive that the following property of a parallelogram and apply theses in problem solving: a. opposite angles are congruent. b. Non- opposite angles are supplementary II. Subject- Matter Reference : Angles of a Parallelogram : Geometry textbook by C.M de Leon pages 123-124 http://regentsprep.org/Regents/math/quad/JavaParallel.htm www.samgierlessons.wikispaces.com Resources : ruler, pencil, internet, protractor, computer, TV A. Introductory activity a. Drill. : What is an angle? What are supplementary angles? b. Review : What is a parallelogram? B. Development of the lesson 1 .( Off-line activity ) Title: REVISITING PARALLEL LINES Activity A 1. Divide the class into four (4) groups. 2. Ask a volunteer to draw parallelogram BANK on the board with its sides extended. 3. Label the angles formed as shown below. 5 6 7 8 B 2 K 1 4 A 3 N 4. Ask each group to answer the following questions orally. a. Name two pairs of opposite angles of parallelogram BANK. b. Name four pairs of consecutive angles c. How are 1 and 6 related? d. How are 7 and 4 related? e. How are 6 and 4 related? f. How are 7 and 1 related? g. How are 7 and 3 related? h. How are 6 and 2 related? 5. Relate the activity with the lesson Activity B. ANGLES OF A PARALLELOGRAM 1. Show a PowerPoint presentation of the figure shown above. 2. Ask the students to share their observations on the figure: Guide them by asking the following questions: a. If m1 =100, what is the measure of the other numbered angle? b. Describe the relation obtained between the following angles - 1 and 3 and 2 and 4 - 2 and 1, 3 and 4, 4 and 1, 3 and 2 c. d. e. f. What do you call 1 and 3? 2 and 4? What is your observation about the opposite angles? What do you call 1 and 2? 2 and 3?1 and 4? 3 and 4? What can be concluded about the consecutive angles? 3. Post Activity Discussion Illustrate the concept further by giving the following exercises: ( In Powerpoint) L O E V 1. LOVE is a parallelogram. a. Name the pairs of opposite angles and consecutive angles. b. Name the pairs of parallel sides. c. If mL = 95, find the measure of the other angles. d. If mL = 3x – 20 and mL = x + 40. Find the measure of each angle. D. Generalization What is true about the opposite angles of a parallelogram? What is true about the non-opposite angles of a parallelogram? IV. Evaluation ( ON LINE QUIZ) C U 40º E T CUTE is a parallelogram. 1. If C = 85º. Find the measure of the other angle? 2. If mT = 2x – 1 and mC = 3x + 5. Find the measure of each angle V. Agreement Answer Test yourself nos. 1- 15, page 127-128 Geometry Textbook Reference: CHAPTER 4, www.samgierlessons.wikispaces.com