1. Welcome Ashim Kanti Das Senior Teacher B N School & College Ctg. Email:ashimkantidas@yahoo.com Ashim Kanti Das Senior Teacher B N School & College Ctg. Email:ashimkantidas@yahoo.com Period:5th Date: 10/04/2014 Venue: B N School & College Ctg.

2. Higher Math Class:9 Time: 40 Minutes

3. A CDB G F E Median Mid-point Median Mid-point

4. Exercise:3.1 Page No:72 Geometry Theorem:7

5. Learning out-comes At the end of this chapter, the students will be able to ………… 1.Explain the conception of orthogonal Projection. 2.Prove and apply the theorems on the basis of theorem of Pythagoras. 3.Prove and apply the theorems of the circumcentre.

6. A E C DB F G

7. Proof: A DCB F E G In ABC, AD is a Median [By Apollonius Theorem] Similarly,

8. A DCB F E G + + [Since, 3 medians are divided 2:1 at G] Or, 3AG = 2AD [By squaring] [Proved]

9. Class Work

10. Home Work P R Q D F E NM In PQR, Three medians PD, QE, RF meet at `O`. PN is perpendicular on the side QR and in PQN, PM is median on the side QN. (a) What do you mean by orthogonal projection ? In PQD, what is the orthogonal projection of PD ? (a) What do you mean by orthogonal projection? In O

11. THANKS