We have an $ABC$ triangle in which $\angle ABD=\angle ACB,AB=12,AD=8,BC=15,DF\perp BC$.How to show that $[BF]\equiv[FC]$
I did a figure in geogebra but i don't see what triangles are similar i know that one angle is equal if I knew $BD=?$ I could show that $ABD$ and $ACD$ triangles are similar from side-angle-side

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