When a particle decays into two, a possible Feynman diagram comes from the interaction of those two particles via exchange of a third one,
thus forming a triangle diagram. Under certain circumstances, those diagrams can give rise to triangle singularities (TS)
that can appear as peaks in the mass distribution of the initial state. These type of peaks can be (and have been) misidentified as
new resonances. Thus, it becomes very important to study the possibility of TS in our reactions. We shall explore the properties of triangle
singularities within the context of hadronic decays and, as an example, we shall analyze the B -> D* pi pi pi and B-> D* pi pi eta processes.
In these two decays, a TS produces visible peaks in the mass distribution and we find measurable branching fractions associated with them.