Question 1018991
The radius of the circular base is 10 cm. This gives a base area of 

{{{(100pi)}}}

The height is 20cm for a slant height (triangle hypotenuse) of

{{{10(sqrt(5))}}}

Area of top section is 

{{{(pi)(r)(slant)}}}

{{{(pi)(10)(10(sqrt(5)))}}}

or 

{{{(100(sqrt(5))(pi))}}}

for a total 

{{{(100(sqrt(5))(pi))}}}+{{{(100pi)}}}


1016.64 sq cm