What is the angle made by the line joining the centre of the sphere and any point on the rim of the circular opening with a vertical line passing through the centre ?
Consider the following for the next two (02) items that follow :<br>A pot is made from a hollow sphere of inner radius 20 cm by cutting its upper portion horizontally. The height of the pot is 30 cm.
- A. \pi/3 ✓
- B. \pi/4
- C. \pi/6
- D. \pi/12
Correct Answer: A. \pi/3
Explanation
The triangle formed by the center, the center of the circular opening, and a point on the rim is a right-angled triangle. The vertical side is 10 and the hypotenuse (radius of the sphere) is 20. \cos \theta = \frac{10}{20} = 0.5 \implies \theta = 60^\circ = \frac{\pi}{3} radians.
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