Respuesta :

Explanation:

The figure shows us ...

  AB ≅ DB

  ∠ABC ≅ ∠DBC

  CB ≅ CB

In order, these are Side, Angle, Side in one triangle being shown congruent to corresponding Side, Angle, Side in the other triangle. This lets us conclude that ...

  ΔABC ≅ ΔDBC by SAS