CLASS IX MATHS PPT
- 2. What it is
- 4. What it is
- 5. it is square
- 6. What it is
- 8. What it is
- 10. Which type of figures these are •
- 11. These are plane figures or 2 dimensional figures •
- 12. What it is
- 13. it is cuboid
- 14. What it is
- 15. it is cube
- 16. What it is
- 17. it is cylinder
- 18. Which type of figures these are •
- 19. These are called solid figures or 3d figures •
- 20. • HOW THESE SOLID FIGURE ARE MADE UP OF
- 21. • THESE SOLID FIGURES ARE MADE UP OF PLANE SURFACES OR PLANE FIGURES
- 22. Side 2 Bottom Back Top Side 1 Front Side 2 Bottom Back Top Side 1 Front Length (L) Breadth (B) Height (H) Cuboid
- 23. • WHEN WE TAKE THE AREA OF THESE PLANE FIGURES AS A SUM , THEN IT IS CALLED THE SURFACE AREA OF THE SOLID FIGURES.
- 24. • NOW LET US DISCUSS THAT HOW TO FIND THE SURFACE AREAS OF CUBOID
- 25. The net L L L L B H H H H L B B B BB H H
- 27. • Total surface Area = L x H + B x H + L x H + B x H + L x B + L x B • = 2 (LxB) + 2(BxH) + 2(LxH) • = 2 ( LB + BH + LH )
- 28. • NOW LET US DISCUSS ABOUT THE SURFACE AREA OF CUBE
- 29. WHAT IS THE DIFFERENCE BETWEEN A CUBOID AND A CUBE
- 30. THE NET FOR THE CUBE
- 31. Cube L L L • Total surface area = 2(LxL) + 2(LxL) + 2(LxL) = 6L2
- 32. AREA OF FOUR WALLS . THIS IS ACTUALLY THE AREAS OF THE SURFACES WHERE THE HEIGHT IS INVOLVED . THIS AREA IS ALSO CALLED THE LATERAL SURFACE AREA • IN CASE OF CYLINDER THIS PART IS CALLED THE CURVED SURFACE AREA BECAUSE THIS PART IS CURVED IN CASE OF CYLINDER
- 33. • LSA OF CUBOID=2(L*H) +2(B*H) = 2(L+B)H LSA OF CUBE =L2 + L2 + L2 + L2 = 4 L2
- 34. PRACTICE QUESTION 1. FIND THE SURFACE AREA OF CUBOIDAL BOX HAVING THE ME ASUREMENT 10cm X 5cm X2cm.
- 35. SOLUTION S A OF CUBOID = 2(LB+BH+HL) = 2(10*5 + 5*2 + 2*10) = 2(50+10+20) = 2*80 =160 CM2.
- 36. PRACTICE QUESTION 2 FIND THE SIDES OF A CUBE WHOSE SURFACE AREA IS 600 CM2.
- 37. SOLUTION S A OF CUBE = 6a2 600cm2= 6 a2 100 cm2= a 2 TAKING SQUARE ROOT BOTH SIDE 10 cm = a EACH SIDE = 10cm.
- 38. LEARNING ACHIEVEMENT TEST 1. APLASTIC BOX 1.5 cm LONG 1.25 cm WIDE AND 65 cm IS TO BE MADE. IT IS OPENED AT THE TOP. IGNORING THE THICKNESS OF THE PLASTIC SHEET, DETERMINE : (A) THE AREA OF THE SHEET REQUIRED FOR MAKING THE BOX (B) THE COST OF THE SHEET FOR IT, IF A SHEET MEASURING 1m2 COSTS Rs 20. 2. THE LENGTH , BREADTH AND HEIGHT OF A ROOM ARE 5m, 4m AND 3m RESPECTIVELY. FIND THE COST OF WHITEWASHING THE WALLS OF T HE ROOM AND THE COST OF CEILING AT THE RATE OF Rs 7.50 PER m2. 3. THE FLOOR OF A RECTANGULAR HALL HAS A PERIMETER 250m. IF THE COST OF PAINTING THE FOUR WALL AT THE RATE OF Rs 10 PER m2 IS Rs 15000, FIND THE HEIGHT OF THE HALL.
- 39. Home Assignment • DISCUSS ABOUT THE DIAGONALS OF CUBOID AND CUBE
- 40. THANK YOU