Assistance with a Geo - Trig question

[IntelxD]

'The combined total surface area of a hemisphere of radius 28mm mounted on top of a right circular cone with slant height 40mm is closest to:'

a) 8444.6 mm^2
b) 9221    mm^2
c) 14146.5 mm^2
d) 16609.5 mm^2

I know that the answer is A however I am not sure how to work it out. If you could provide an answer with your explanation I would be very grateful.

[keltingmeith]

TSA of a sphere is , so the TSA of a hemisphere is half that.

The TSA of a cone is , minus the circle that's normally present, is .

So, the TSA of our shape is . Plugging in r=28 and h=40, we get A.

[IntelxD]

TSA of a sphere is , so the TSA of a hemisphere is half that.

The TSA of a cone is , minus the circle that's normally present, is .

So, the TSA of our shape is . Plugging in r=28 and h=40, we get A.

Thank you very much.