Are you sure you have written the question correctly/fully.
B and D are on different triangles. If the are arranged as a reflection and we need to work out that then you need to state that.
Correct this and I will help.

Ok, if we assume that the the sides which are similar are BC and DE and BC = 1.5 and DE = 9. the ratio between the two is 1:6 (got by dividing the large by the smaller). this ratio MUST be the same for each other side.
we also know AB = 2. This means AD = 2x6=12.
the length of BD = length of AD - length of AB
= 12 - 2
=10

Hope this helps

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