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The radius of a right circular cone is 3 cm and its height is 4 cm. The total surface area of the cone is
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- 48.4 sq.cm
- 64.4 sq.cm
- 96.4 sq.cm
- 75.4 sq.cm
- 48.4 sq.cm
Correct Option: D
OB = 3 cm
OA = 4 cm
∴ AB = l
= √3² + 4² = √9 + 16
= √25 = 5 cm
∴ Total surface area = πrl + πr² = πr(l +r)
| = | × 3(5 + 3) | |
| 7 |
| = | × 3 × 8 = 75.4 sq.cm. | |
| 7 |
