find the total surface area of a solid hemisphere whose radius is 21cm?

Answer 1

The surface of a full sphere is 4πr^2. The round part of the hemisphere is then half that, or 2πr^2. The flat part is πr^2. The total area is then (2 + 1)πr^2 = 3πr^2

EDIT NOTE: (4/3)πr^3 is the VOLUME of a sphere.

Answer 2

Solid Hemisphere

Answer 3

To see this shape, imagine a bowl with a lid. To find the surface area, you need to add the area of the bowl and the area of the lid. The bowl is going to be half of a sphere. The equation for the surface area of a sphere is 4*pi*r^2. You need to find it for half a sphere, so you can use 2*pi*r^2. Then you have to add the surface area of the lid, which is just a circle, so it's pi*r^2. You just have to do some plugging in... but I'm leaving that to you.. don't want to give you the answer =Þ

Answer 4

The formula is 3 x pi x r^2

Answer 5

Curved surface area = 2π r² = 2π x 21² cm²
Curved surface area = 2769 cm²
Area of circle = πr² = π x 21² cm² = 1385 cm²
Total surface area = 4154 cm²

Answer 6

4/3*pi*r^3 this is the area of a sphere dvide it by 2 to get the area of hemesphere.
pi*r^2 the area of the circular bottom of the hemesphere if u want to add it

Answer 7

4/3pir^3 is the surface of a bal with radius r
so 2/3pi(21)^3 is he surface of half a ball ( a hemisphere )
the ground surface is pir^2 = pi(21)^2 you have to add that with the previous number i explained.

good lucjk with your geometric carreer

Answer 8

[(4pi)rsq/2]=2pirsq=2*3.14*21*21=2,769.48 cm (squared)

Answer 9

what question for "ting tong"