10 questions · Form 2 Mathematics Bab 6: Three-Dimensional Geometric Shapes
A cuboid has dimensions 8 cm × 5 cm × 4 cm. What is its total surface area?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. A cuboid has dimensions 8 cm × 5 cm × 4 cm. What is its total surface area?
Answer: A
Surface Area = 2(lb + bh + lh) = 2(8×5 + 5×4 + 8×4) = 2(40 + 20 + 32) = 2(92) = 184 cm².
2. 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.
3. 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.
4. 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.
5. If the length of every edge of a cube is doubled, by what factor does its volume increase?
Answer: D
Volume scaling factor = 2³ = 8 times.
6. 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.
7. Which 3D shape has two congruent circular bases and one curved surface?
Answer: B
A cylinder consists of two parallel, congruent circular bases connected by a curved surface.
8. 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.
9. 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).
10. The volume of a cuboid is 240 cm³. If its base area is 30 cm², find its height.
Answer: B
Volume = Base Area × Height => 240 = 30 × Height => Height = 24030 = 8 cm.