01 mathematics
- 2. Pupil Teacher’s Name: Jaspreet Kaur Pupil Teacher Roll No.: 100 Subject: Mathematics Class: VII Topic: Angle sum property of Quadrilateral Duration: 35 Minutes
- 3. General Aids A well Equipped Class Room with Chalk Board, Duster, Pointer etc. Specific Aids A model showing sum of four angles of quadrilateral is 3600 (Angle sum property of quadrilateral) Instructiona l Objectives • To develop cognitive, conative and affective abilities of students. •To develop various skills, values and attitude in students. General Aims • To Develop the reasoning, thinking & imagination powers of the students. •To Enable them to make use of the mathematical knowledge in day-to-day life. •To provide opportunity for the development of creative powers.
- 4. General Objective To make students to know about that sum of the four angles of Quadrilateral is 3600. Specific objectives After the completion of topic, the students will be able to 1. Prove angle sum property of Quadrilateral. 2. Solve problems based on angle sum property of Quadrilateral. Previous knowledge assumed 1. Pupils are well acquainted with triangles. 2. They are well acquainted with angle sum property of triangle. 3. They are well acquainted with Quadrilateral. Previous knowledge Testing Pupil Teacher will ask the following questions -
- 5. Previous Knowledge Testing Questions Answers 1. Name this figure (by showing Triangle) 2. What is the Angle Sum property of triangle? 3. Name this figure (by showing another triangle) 4. Name this figure? (By placing another triangle on previous triangle that makes it Quadrilateral). 5. What is the sum of the angles of a Quadrilateral? 6. How will you prove this? Triangle Sum of three angles of triangles is equal to 1800 Triangle Quadrilateral 3600 No Response Announcement of Topic On finding the most of the students unable to answer the last question satisfactory. P.T. will announce the topic by saying, well students today we’ll discuss how to prove angle sum properly of Quadrilateral.
- 6. Presentation P.T. will use Lecture – Cum – Demonstration Method. Black Board work was done side by side. Relevant teaching aid will be used whenever required.
- 7. Subject Matter P.T. Activity Pupil Response Chalk-Board Work In Quadrilateral ABCD, we have two triangles, ∆ ABC & ∆ ACD In ∆ ACB - Mark A= 1 & C = 3 In ∆ ACD , A= 2, C=4 Name the first triangle in this figure which is blue in Colour? Name the second ∆ in this figure which is pink in colour? What is the sum of Three angles of ∆ABC? ∆ ABC ∆ ACD 1+B+C=1800 ∆ ABC Mark A= 1 & C = 3 In ∆ ACD , A= 2, C=4 Sum of all angles of triangles is 1800. What is the sum of three angles of ∆ADC? 2+D+4= 1800 In ∆ABC 1+B+C=1800 ……..(1)
- 8. Subject Matter P.T. Activity Pupil Response Chalk-Board Work i.e. In ∆ADC 1+B+3 = 1800 ……..(1) In ADC 2+D+4 = 1800 ……(2) Add (1) & (2) 1+B+3 +2+D+4 = 1800 + 1800 (1 + 2) + B +(3+4 ) +D = 3600 Therefore A+B+C +D = 3600 What is 1800+1800? What is 1 + 2? What is 3 + 4? 3600 A C Add (1) & (2) 1+B+3 +2+D+4 = 1800 + 1800 (1 + 2)+B+ (3+4)+D = 3600 Therefore A+B+C +D = 3600
- 9. Subject Matter P.T. Activity Pupil Response Chalk-Board Work Question based on Angle sum property of Quadrilateral. Three angles of quadrilateral are 1350, 600, 750 respectively Find Fourth Angle What is angle sum property of quadrilateral ABCD? What is the value of A? What is the value of B? What is the value of C? A+B+C+D = 3600 1350 600 750 D C X0 750 1350 600 A B Let in Quadrilateral ABCD A=1350, B=600 C=750 & D=X0 Now A+B+C+D = 3600 (Angle sum property of Quadrilateral 1350+600+750+X0=36 00 2700+X0=3600 X0 = 3600-2700 X=900 , D=900
- 10. Subject Matter P.T. Activity Pupil Response Chalk-Board Work Sectional Recapitulation • What is angle sum property of Quadrilateral? • In a Quadrilateral ABCD, D=1200, A=400, B=400 Find forth angle i.e. C The Four angles of a Quadrilateral are in the ratio of 1:2:3:4. find all the four angles. What is angle sum property of Quadrilateral ABCD? What is the value of A? What is the value of B? What is the value of C? A+B+C+D = 3600 X0 Y0 3X0 Let A= X0 B = 2X0 C = 3X0 D = 4X0 A+B+C+D = 3600 X0+2X0+3X0+4X0= 3600 10X0 = 3600 X0 = 3600/100 X0=360 A = X0= 360 B = 2X0 = 2(36)0 = 720
- 11. Subject Matter P.T. Activity Pupil Response Chalk-Board Work What is the value of D? What is the Value of X0? 4X0 360 C =3X0 =3(360) =1080 D = 4X0 =4(360) =1440 A=360 B=720, C=1080 D=1440
- 12. Final Recapitalization: If three angles of a Quadrilateral are in the ratio of 1:2:3. If the sum of smallest and largest angle from these angles is 1800 then find all the angles of quadrilateral. Home Work: The four angles of a quadrilateral are in the ratio 2:3:4:5. Find all the angles.
- 13. Audio Visual Aid Used: D C 4 3 D 4 C 3 2 1 2 1 A B A B