Total Surface Area of Cone | Exercise 13.3 | Q2

Question 2: Find the total surface area of the cone, if its slant height is 21 m and diameter of its base is 24 m.

Explanatory Answer | Exercise 13.3 Q2

Total surface area of a cone = π × r × (l + r)
Slant height of the cone, l = 21 m.
Diameter of the cone = 24 m
So, Radius of the cone , r = 12 m

Take π = \\frac{22}{7})
Total surface area of the cone = \\frac{22}{7}) × 12 × (21 + 12)
= \\frac{22}{7})×12 ×33
= 1244.57 m²

Exercise 13.1 | Surface Area of Cubes & Cuboids

1. Class 9 Exercise 13.1 Question 3 | Height of hall ▶
2. Class 9 Exercise 13.1 Question 6 | TSA of Herbarium ▶
3. Class 9 Exercise 13.1 Question 7 | Shanti Sweets ▶

Exercise 13.2 | Surface Area of Cylinders

1. Class 9 Exercise 13.2 Question 3 | CSA TSA of Metal Pipe ▶
2. Class 9 Exercise 13.2 Question 4 | Roller & Playground ▶
3. Class 9 Exercise 13.2 Question 9 | Cylindrical Petrol Tank ▶
4. Class 9 Exercise 13.2 Question 10 | CSA of Decorative Lampshade ▶

Exercise 13.3 | Surface Area of Cones

1. Class 9 Exercise 13.3 Question 5 | Length of Tarpaulin 3 m wide ▶
2. Class 9 Exercise 13.3 Question 8 | Cost of painting conical barricades ▶

Exercise 13.4 | Surface Area of Spheres & Hemispheres

1. Class 9 Exercise 13.4 Question 8 | Outer CSA of hemispherical bowl ▶
2. Class 9 Exercise 13.4 Question 9 | Surface area of sphere & Cylinder ▶