Question

Hey anyone!!!

Answer if you know.

If the external and internal radii of a hollow hemisphere are R and r respectively , then it's T.S.A is (3 R²-r²)π . Is it true ? Justify your answer.

Answer 1

heyyyy mate..

here is your answer..


we know that it's a form of like tube

so π(R^²-r^²)

we know that volume of hemisphere= 3πr^²


so total surface area= (3R^²-r^²)

it's true

hope it help you

Answer 2

no it's wrong because for TSA we will find the all area can be seen
first is external surface area :-
2 ×pi× R^2
second is internal surface area :-
2×pi× r^2
third is the area of the thickness of hemisphere from top :-
pi(R^2-r^2)


now for total surface area we will add them all togther :-
TSA=2×pi×R^2 + 2×pi×r^2 + pi(R^2-r^2) =pi (3R^2+r^2)