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For the rocket shown in the figure, what area is painted yellow? The cylindrical part has radius $1.5\,\mathrm{cm}$ and height $20\,\mathrm{cm}$, and take $\pi=3.14$. 
A$188.4\,\mathrm{cm}^2$
B$195.465\,\mathrm{cm}^2$
C$201.75\,\mathrm{cm}^2$
D$63.585\,\mathrm{cm}^2$
Answer & Solution
Correct answer: B. $195.465\,\mathrm{cm}^2$
The yellow region consists of the curved surface of the cylinder and one exposed circular base at the bottom. So area $=2\pi r'h'+\pi {r'}^2=2\pi(1.5)(20)+\pi(1.5)^2=195.465\,\mathrm{cm}^2$. Option D is the orange area, not the yellow one.
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