10 questions · Form 2 Mathematics Bab 6: Three-Dimensional Geometric Shapes
Find the total surface area of a solid hemisphere with radius 7 cm. (Take π = 227)
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Find the total surface area of a solid hemisphere with radius 7 cm. (Take π = 227)
Answer: A
Total surface area of a solid hemisphere = Curved area + Circular base area = 2πr² + πr² = 3πr² = 3 × (227) × 7² = 3 × 154 = 462 cm².
2. What shape is formed by the net consisting of 1 square and 4 identical isosceles triangles?
Answer: B
A square base combined with 4 triangular lateral faces forms a square-based pyramid.
3. Calculate the volume of a cylinder with radius 7 cm and height 10 cm. (Take π = 227)
Answer: A
Volume = πr²h = (227) × 7² × 10 = 154 × 10 = 1540 cm³.
4. Find the total surface area of a closed cylinder with radius 7 cm and height 3 cm. (Take π = 227)
Answer: A
Surface Area = 2πr² + 2πrh = 2(227)(7²) + 2(227)(7)(3) = 308 + 132 = 440 cm².
5. Find the volume of a cone with radius 7 cm and height 12 cm. (Take π = 227)
Answer: A
Volume = 13 πr²h = 13 × (227) × 7² × 12 = 13 × 154 × 12 = 154 × 4 = 616 cm³.
6. Calculate the total surface area of a cube with side length 5 cm.
Answer: D
A cube has 6 square faces. Total surface area = 6 × (5)² = 6 × 25 = 150 cm².
7. Calculate the surface area of a sphere with radius 21 cm. (Take π = 227)
Answer: A
Surface Area = 4πr² = 4 × (227) × 21² = 4 × (227) × 441 = 5544 cm².
8. Calculate the volume of a sphere with radius 3 cm. (Take π = 227)
Answer: C
Volume = 43 πr³ = 43 × 227 × 3³ = 43 × 227 × 27 = 36 × 227 = 7927 = 113 17 cm³ (or 113.14 cm³).
9. A cylinder has a volume of 308 cm³ and a height of 8 cm. Find its radius. (Take π = 227)
Answer: A
Volume = πr²h => 308 = (227) × r² × 8 => 308 = (1767)r² => r² = 308 × 7176 = 12.25 => r = 3.5 cm.
10. Calculate the volume of a hemisphere with radius 7 cm. (Take π = 227)
Answer: A
Volume of hemisphere = 23 πr³ = 23 × (227) × 7³ = 23 × 22 × 49 = 21563 ≈ 718.67 cm³.