Answer: 154/3 cm².
- A 154/3 cm²
- B 77/3 cm²
- C 22 cm²
- D 44 cm²
Correct answer: A. 154/3 cm²
Explanation: Area = (θ/360°) × πr² = (60/360) × (22/7) × 49 = (1/6) × 154 = 154/6 = 77/3. Wait: (1/6) × 22 × 7 = 154/6 = 77/3 cm².
Three standard 3D solids and their key formulas: a cylinder's volume scales with the full height, a cone's volume is exactly one-third of the cylinder with the same base and height, and a sphere's volume and surface area both follow distinct r-based formulas worth memorising separately.
Concept context
Perimeters, areas, and volumes of 2D and 3D shapes