Question

Find the volume and surface area of the composite figure. Give four answer in terms of π. HELP NEEDED NOW!!! THE RED IS THE ONE I GOT WRONG!!

Answer 1

Divide the figure above into a cylinder and a dome

+) the volume of the dome is

`v1 = (1)/(12) \pi6 {}^(3) = 18\pi`

the surface area is

`s1 = \pi3 {}^(2) = 9\pi`

+) the volume of the cylinder is

`v2 = \pi.3 {}^(2) .13 = 117\pi`

the surface area is

`s2 = 2\pi.3.13 + 2\pi.3 {}^(2) = 96\pi`

so the volume of this figure is

`v = v1 + v2 = 18\pi + 117\pi = 135\pi`

the surface area of this figure is

`s = 9\pi + 96\pi = 105\pi`