Question:
Tick (✓) the correct answer:
The height of a cylinder is 80 cm and the diameter of its base is 7 cm. The whole surface area of the cylinder is
(a) 1837 cm2
(b) 1760 cm2
(c) 1942 cm2
(d) 3080 cm2
Solution:
(a) $1837 \mathrm{~cm}^{2}$
Diameter $=7 \mathrm{~cm}$
Radius $=3.5 \mathrm{~cm}$
Height $=80 \mathrm{~cm}$
$\therefore$ Total surface area $=2 \pi \mathrm{r}(\mathrm{r}+\mathrm{h})=2 \times \frac{22}{7} \times 3.5(3.5+80)=22(83.5)=1837 \mathrm{~cm}^{2}$