00:02
Determine the surface area of a cylinder.
00:04
We need two key pieces of information.
00:07
Information on the cylinder's radius labeled r and its height labeled h.
00:14
In the given problem, we are given the diameter of the cylinder, which is equal to four yards, but we need a radius from that.
00:25
So we can use this formula down here, and we now know that the radius is equal to two yards.
00:34
We also need the height of the cylinder, which in the problem was not given.
00:39
So i'm going to assume a height of two yards as well, just to make sure that we can get to a final number in this video.
00:49
So the first step is going to be calculating the information about the circle.
00:55
So the circle on the top and the bottom of the cylinder has a radius, which will give us an area of the circle, the circumference of the circle.
01:06
Both of those pieces of information are critical to be able to get to the surface area.
01:11
So first, let's solve for the area of the circle.
01:16
So we can use the formula listed, which is pi r squared, and then giving in our numbers for radius.
01:27
2 squared is 4 times pi is roughly 12.
01:35
And then we can calculate the circumference of the circle and by doing 2 pi r, which because our radius is still 2 yards, is also going to be 12 yards...