Parallel Lines in an Isosceles Triangle: Are DA and BF Parallel?

Question

The triangle ABC is isosceles.

Is the line segment DA parallel to BF?

00:00 Is DA parallel to BF?

00:03 Alternate angles are equal between parallel lines

00:34 Therefore the lines are parallel

00:42 The extensions of parallel lines are also parallel

00:45 And this is the solution to the question

Yes