2010 · Q97
(For the next three questions to follow):
Let C be a right-circular cone. It is given that the two ends of a frustum of C are of radii 3 cm and 6 cm, and the height of the frustum is 9 cm.
What is the total surface area of the given frustum ?
Elementary MathematicsMensuration
- A9π(2√10 + 5) cm²
- B9π(3√10 + 5) cm²
- C9π(3√10 + 4) cm²
- D27π(√10 + 1) cm²
Explanation
π(9)(3√10)+9π+36π=9π(3√10+5).