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A conical hat is to have base radius 8 cm and slant height 30 cm. Paper area required is approximately:
Answer & Solution
Correct answer: D.
1. Only the curved surface is needed, since a hat has no base.
2. Curved surface area = πrl = π × 8 × 30.
3. = 240π cm².
4. Numerically about 754 cm² (≈ 240 × 3.14), but expressed in π form it is 240π cm².
5. So the paper needed is 240π cm².
_Source: SCERT Kerala Std X Mathematics Part-2, Chapter 7-8 (pp 180-199, 2019 ed.)._
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