Does anybody know how to fill in all the boxes?

Step-by-step explanation:

# angle ABC is congruent to angle DEF which’s given

# angle GHI is congruent to DEF which’s given

#angle DEF is congruent to DEF / symmetric property

# angle ABC is congruent to GHI / transitive property

(ABC+DEF=DEF+GHI)

- SUBTRACT DEF from both sides

ABC=GHI

i think it might be a but you might want a second opinion