00:02
Right, so we've got a polygon on the base of a prism with n sides.
00:11
So there we go.
00:13
So 1, 2, 3, 4, 5, 6.
00:15
So that's n equals 6, but let's just pretend that this is n in general.
00:21
So we fundamentally here we have n vertices, right? so, vertices equals at this point, it's n, right? and then we make it into a prism.
00:41
We've got the point up here, and we put all the points up there, right? draw all the lines connecting up to the top of the prism.
00:58
Well, so vertices equals n.
01:00
Now let's talk faces.
01:04
All of the end points correspond to a face in this top part of the prism, and then there's that face below, right? so the faces equal n plus 1, right? and for the vertices, that n was just the vertices in the bottom.
01:28
So we need to count that top vertex, too.
01:30
So there's n plus 1.
01:32
Now we need to know about edges.
01:36
Well, if it's a polygon of n sides, then edges, we're going to have n in the bottom, right? n edges in the bottom, plus those n edges, you know, these n edges that lead up to the top of the polygon, or the top of the prism, right? so that's an additional n.
02:08
So that's 2n.
02:12
2n...