Question

Theorem: A line parallel to one side of a triangle divides the other two proportionately.

In the figure below, segment DE is parallel to segment BC and segment EF is parallel to AB.



Which statement can be proved true using the given theorem?

Segment BF = 16

Segment BD = 18

Segment BD = 20

Segment BF = 15

Answer 1

the theorem means that the legs AB and AC are divided in a proportion
so you can say
\[ \frac{12}{15}= \frac{x}{25} \]
where x is segment BD

Answer 2

So its segment BD=20 ?