Which is greater, the volume of a hemisphere with
radius 2 cm or the total volume of two cones with
radius 2 cm and height 2 cm?

Question

anonymous · Answer

sphere is 4/3 pi r^3    hemisphere is 1/2 of a sphere.

cone is  1/3 area of the base * height.

SO

hemisphere is 1/2 * 4/3 * 3.14 * 2^3
                   is 16.746666  cm^3

cone is  1/3   (pi r^2) * height
             1/3 * pi * 2^2 * 2
         is  8.37   BUT you have to cones
       so  2 * 8.37 =  16.746666

They are the same...