Question

all formals from chapter 13 class 9​

Answer 1

Answer:

Formula's of Ch. 13 = Surface Areas and Volumes

1. Cuboid ;

• Total Surface Area of cuboid =

2(lb + bh + hl)

• Lateral Surface Area of cuboid =

2 × (l + b) × h

• Area of 5 phases = 2 (l + b) h + lb

• Volume of cuboid = l × b × h

2. Cube ;

• Total Surface Area of cube = 6a²

• Lateral surface area of cube = 4a²

• Area of 5 phases = 5a²

• Volume of cube = a × a × a = a³

3. Cylinder ;

• Curved surface area of cylinder = 2πrh

• Total surface area of cylinder =

2πr (h + r)

• Volume of cylinder = πr²h

4. Sphere ;

• Surface area of sphere = 4πr²

• Volume of sphere = 4/3 πr³

5. Hemisphere ;

• Curved surface area of hemisphere = 2πr²

• Total surface area of hemisphere = 3πr²

• Volume of hemisphere = 2/3 πr³

6. Cone ;

• Curved surface area of cone = πrl

• Total surface area of cone = πr (l+r)

• Volume of cone = 1/3 πr²h

Hope it helps you :)