Mensurationhard · Past Paper
The radius and height of a cone are in the ratio 3:4. If its curved surface area is 188.4 cm², find its radius (Take π = 3.14).
A3 cm
B6 cm
C9 cm
D12 cm
✓ Correct Answer: B — 6 cm
r=3x, h=4x, so l=5x. CSA = πrl = 3.14 * 3x * 5x = 47.1x² = 188.4 => x² = 4 => x = 2. r = 3 * 2 = 6 cm.
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