00:01
Okay, so suppose i have the following solid.
00:03
Note that i have a hemisphere or half of a sphere and a cone.
00:08
I wanna find the volume.
00:10
Well, i'm gonna find the volume of the hemisphere.
00:13
I know that the volume of a sphere is 4 3rds pi r to the 3rd, and it's a hemisphere, so it's half of that.
00:19
So divided by two, or i could just multiply this by 1 1.
00:24
So what is the radius of the sphere? well, i have to figure that out.
00:29
I know that all the way across is 18 inches, okay? so then half of that would be approximately nine inches, because that'll be the diameter.
00:39
It goes down, half of that is nine, so this will be 4 3rds pi times nine to the 3rd times 1 1.
00:46
And let's leave this in terms of pi for now.
00:50
So this will be approximately four times nine, 2 ,916 all divided by three times two, which is six pi...