Answer: π(abc/4K)².
- A π(abc/4K)²
- B π × abc/4K
- C πabc/2
- D 4πK/abc
Correct answer: A. π(abc/4K)²
Explanation: Circumradius R=abc/(4K) where K is triangle area. Area of circumscribed circle=πR²=π×[abc/(4K)]²=π(abc/4K)². Ans: π(abc/4K)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