FC keeps going like that and line BD right here is a transversal then whatever this angle is this angle is going to be as well for alternate interior angles which we've talked a lot about when we first talked about angles with transverals and all of that so these two angles are going to be the same but this angle and this angle are also going to be the same because this angle and that angle are the same this is a bisector and because this is a bisector we know that angle ABD is the same as angle DBC so whatever this angle is - that angle is and so is this angle and that gives us kind of an interesting result because here we have a situation where if we look at this larger triangle