- A14
- B7
- C21
- D3.5
Step-by-Step Solution
The curved edge of the sector becomes the rim of the cone. Arc length = (120/360) × 2π × 21 = 14π cm. Setting 2πr = 14π gives r = 7 cm.
Answer: B) 7
A sector cut from a circle of radius 21 cm has a central angle of 120°. Its two straight edges are brought together and joined to form a cone. Find the radius of the base of that cone in cm.
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