Question:
A cylinder of same height and radius is placed on top of a hemisphere. Find the curved surface area of the shape if the length of the shape is 7cm.
Solution:
Given length of the shape = 7cm
But length = r + r
2r = 7cm
r = 3.5 cm
Also; h = r
Total surface area of shape $=2 \pi r h+2 \pi r^{2}$
$=2 \pi r r+2 \pi r^{2}$
$=2 \pi r^{2}+2 \pi r^{2}$
$=4 \times 22 / 7 \times(3.5)^{2}=154 \mathrm{~cm}^{2}$