Answer: 2πr(r+h).
- A 2πrh
- B πr²h
- C 2πr(r+h)
- D πr(r+h)
Correct answer: C. 2πr(r+h)
Explanation: TSA of cylinder = 2πr² (two circles) + 2πrh (curved surface) = 2πr(r+h).
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