2025 · Q69
Consider the following for the next two items that follow: The angle at the vertex of a conical body is 120°. What is the ratio of the radius of the conical body to its slant height?
Elementary MathematicsMensuration
- A1 : 2
- B3 : 1
- C3 : 2
- D2 : 1
Explanation
The semi-vertical angle is half the vertex angle, i.e. 60 degrees. For a right circular cone, radius/slant height = sin(semi-vertical angle) = sin 60 = sqrt(3)/2. So the ratio r : l is sqrt(3) : 2, which is option (c) with '3' denoting sqrt(3).