Okay, for this proof, I'll write the steps out.
Statements:
1. ABCD is a parallelogram
2. FG bisects DB
3. <GEB ≡ (pretend congruent symbol) <FED
4. DE ≡ BE
5. <CDA ≡ <ABC
6. < CDB ≡ <DBA
7. triangle DFE ≡ triangle BGE
8. FE ≡ GE
9. DB bisects FG
Reasons:
1. Given
2. Given
3. vertical angles are congruent
4. If bisected, then split into congruent parts
5. opposite angles of a parallelogram are congruent
6. Subtraction Property
7. ASA
8. CPCTC
9. segment split into congruent parts by other segment is bisected.
Hope this helped! :)