Answer: a√2.
- A a
- B 2a
- C a√2
- D a/√2
Correct answer: C. a√2
Explanation: Diagonal of square = a√2 (Pythagorean theorem: √(a²+a²) = a√2).
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