00:01
So in this problem, we're asked to find the volume and surface area of both of these cylinders.
00:06
So i'm first going to start with a here, find the volume, which is pi, r.
00:13
So that would be, since the whole diameter is 9, half of 9 would be 4 .5 for r, so 4 .5 squared, times the height, which is 12.
00:25
And i'm going to go ahead and multiply 4 .5 squared times 12, and keep that in.
00:32
In terms of pi, so 243 pi would be the volume.
00:37
And that would be units cubed.
00:39
Now for the surface area, i'm gonna do two pi r squared, so 4 .5 squared, plus 2 pi rh, so 4 .5 times 12 for the height.
00:58
And i'm gonna square 4 .5 again, and multiply that by 2, which is 40 .5 pi plus, and then 2, times 4 .5 times 12 gives me 108 pi.
01:15
And then i'm going to combine those together, which is 148 .5 pi for the surface area.
01:25
Okay, so let's do the same thing for b...