2014 · Q88
For the next three (3) items that follow: A right triangle having hypotenuse 25 cm and legs in the ratio 3 : 4 is made to revolve about its hypotenuse. (π = 3.14) What is the surface area of the double cone so formed?
Elementary MathematicsMensuration
- A1101.2 cm²
- B1111.4 cm²
- C1310.4 cm²
- D1318.8 cm²
Explanation
Curved surface = πr(l₁ + l₂) = π·12·(15 + 20) = 420π = 1318.8 cm².