ABC26GN4944 · Volume and Surface Area
Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
The curved surface of a right circular cone of height 15 cm and base diameter 16 cm is
(a)$60 \pi \mathrm{cm}^{2}$
(b)$68 \pi \mathrm{cm}^{2}$
(c)$120 \pi \mathrm{cm}^{2}$
(d)$136 \pi \mathrm{cm}^{2}$
Answer
Explanation
$h=15 \mathrm{cm}, r=8 \mathrm{cm}$. So, $l=\sqrt{r^{2}+h^{2}}=\sqrt{8^{2}+(15)^{2}}=17 \mathrm{cm}$. $$\begin{aligned} & \therefore \text { Curved surface area }=\pi r l=(\pi \times 8 \times 17) \mathrm{cm}^{2} \\ & \quad=136 \pi \mathrm{cm}^{2} . \end{aligned}$$
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