00:01
So we have a diagram here of three parallel lines intersecting two transversals.
00:10
And we want to find, from the givens, the length of line segment bc, labeled there as x.
00:20
So we have transversals ac and fd transversals.
00:39
And we have the parallel lines, a, f, b, e, and c, d.
00:53
They're all parallel to each other.
00:56
So to find x, we're going to use something called transversal proportionality, which states that if you have three or more parallel lines intersecting two transversals, then those parallel lines divides the transversals into proportional segments.
01:24
So based on that theorem, we have that ab, line segment ab over segment b, will be proportional to line segments, f .e and e .d.
01:43
So we can just start plugging in values for these lines segments...