Question

A sphere is melted and recast into a hemisphere.
Show that the ratio of surface area of sphere to
that of hemisphere is 4:334.
[4]​

Answer 1

Answer:

TSA of solid sphere =4πr

2

TSA of hemi-sphere =2πr

2

+πr

2

=3πr

2

Required ratio =4πr

2

:3πr

2

=4:3