00:01
Okay, so euler's formula is the vertices minus the number of edges plus the number of faces equals two.
00:15
And we have to count all these for that figure in the book and make sure that it's consistent.
00:21
So let's do that.
00:23
I'm not going to copy over this figure because i'm not allowed to copy and paste, and i doubt whether i could draw it.
00:28
But let's count this.
00:29
So number of vertices first.
00:31
So that's number of corners.
00:34
So i'm counting, let's see, one, two, three, four, five, six, seven, eight.
00:42
Okay, so we've got eight vertices minus the number of edges...