00:01
Okay, so in question a, we're looking to see whether the floor of the tree house is parallel to the ground.
00:13
Well, if the floor wasn't parallel to the ground, we'd be in big trouble.
00:18
Things would keep falling off.
00:19
So this one is probably the easiest of the questions that are established so far.
00:25
The floor and the ground should never intersect.
00:29
That would mean that the house is falling down.
00:31
So that would be bad if that was happening.
00:33
The second question says that the lines containing the railings of the staircase, such as a -b, right? so the staircase is actually on a diagonal down like this, right, are skewed to the lines in the plane containing the ground.
00:53
So in this case, right, you've got the ground, right? and you've got this whole surface of the ground area.
00:59
Well, unfortunately, not all of the lines on the ground will be skew to this line.
01:07
At some point, this is going to intersect a line.
01:11
I mean, there's an infinite number of lines it will hit...