00:01
So we want to see if this triangle, first of all, we have two triangles here.
00:03
We kind of draw a little picture here.
00:05
And we know that this side is parallel to this side.
00:10
And this one is marked as 8.
00:12
This one is marked as 5.
00:15
This one is marked as 13.
00:17
And this is marked as x.
00:18
And yes, this triangle, this upper triangle, and this larger triangle will be similar triangles.
00:25
We would show that by angle, angle, angle.
00:27
Because these two angles are going to be congruent because they are corresponding angles for parallel lines.
00:35
And these two angles are going to be congruent, and this angles congruent to itself.
00:40
So this upper triangle and the lower triangle are similar.
00:43
And the common mistake that people make when they set up the proportion is we look at the similar sides...