Answer: 6a².
- A 4a²
- B 6a²
- C 8a²
- D a³
Correct answer: B. 6a²
Explanation: Cube has 6 faces, each area a². Total SA = 6a².
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