Question:
If two solid hemispheres of same base radius r are joined together along their bases, then curved surface area of this new solid is
(a) 47πr2
(b) 6πr2
(c) 3πr2
(d) 8πr2
Solution:
(a) Because curved surface area of a hemisphere is 2 w2 and here, we join two solid hemispheres along their bases of radius r, from which we get a
solid sphere.
Hence, the curved surface area of new solid = 2 πr2 + 2 πr2 = 4πr2