Answer:
∠ABD ≅ ∠DBC - Given.
∠ABD and ∠DBC are complimentary angles - Given.
∠ABD + ∠DBC = 90° - Definition of complimentary angles.
∠ABD + ∠DBC = ∠ABC - Angle addition postulate.
∠ABC = 90° - Substitution property.
∠ABC is a right angle - Definition of a right angle.
~Hope this helps!~
