Answer: 154 cm².
- A 154 cm²
- B 44 cm²
- C 49 cm²
- D 22 cm²
Correct answer: A. 154 cm²
Explanation: Area = πr² = (22/7) × 49 = 154 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