Question 1011361


You must know that the surface area of a sphere is {{{4pi*r^2}}}.

A {{{hemisphere}}} is {{{half}}} of a {{{sphere}}}, this must mean that the curved surface area of a hemisphere is the surface area of a sphere divide by {{{2}}}. 
That is {{{4pi*r^2/2}}} which gives the following expression: 

 {{{Curved_ Surface_ Area =2pi*r^2}}} 


Total Surface Area of Hemisphere includes the circular base  below the curve and its area is {{{r^2*pi }}}, so

{{{Total _Surface _Area _of_ Hemisphere =2pi*r^2+r^2*pi }}}

if the large has diameter {{{22cm}}}, then its radius is {{{11cm}}}, and

{{{Total _Surface _Area _of_ larger_Hemisphere =2pi*(11cm)^2+(11cm)^2*pi }}}

{{{Total _Surface _Area _of_ larger_Hemisphere =2pi*121cm^2+121cm^2*pi }}}

{{{Total _Surface _Area _of_larger_ Hemisphere =pi*242cm^2+121cm^2*pi }}}

{{{Total _Surface _Area _of_larger_ Hemisphere =363cm^2*pi }}}

if their bases touching each other, then the area of the bases of smaller hemisphere will be already included in the area of the bases of greater hemisphere; so for smaller hemisphere we will need only curved surface area 

and if the smaller has diameter {{{12cm}}}, then its radius is {{{6cm}}}, and

{{{Curved_ Surface_ Area_of_smaller_ Hemisphere  =2pi*(6cm)^2 }}}

{{{Curved_ Surface_ Area_of_smaller_ Hemisphere  =2pi*36cm^2 }}}

{{{Curved_ Surface_ Area_of_smaller_ Hemisphere  =72cm^2*pi }}}

and, total surface area of both hemispheres will be:

{{{Total _Surface _Area _of_larger_ Hemisphere+Curved_ Surface_ Area_of_smaller_ Hemisphere  =363cm^2*pi +72cm^2*pi}}}

{{{Total _Surface _Area _of_larger_ Hemisphere+Curved_ Surface_ Area_of_smaller_ Hemisphere  =435cm^2*pi}}}