1. <AEP is congruent to <IEC -Vertical <s are congruent
2. <APE is congruent to <CIE - When two parallel lines are cut by a transversal, alternate interior ,s are congruent.
3. Triangle APE is similar to triangle CIE - Angle Angle similarity postulate
4. EA/EC=AP/CI - Corresponding sides of similar triangles are proportionate
5. <BFH is congruent to <AFP - Vertical <s are congruent
6. <FHB is congruent to <FPA -When two parallel lines are cut by a transversal, alternate interior ,s are congruent.
7. Triangle BFH is similar to triangle AFP- Angle Angle similarity postulate
8. BF/AF=BH/AP- Corresponding sides of similar triangles are proportionate
9. <BPD is congruent to <BIC - When two parallel lines are cut by a transversal, Corresponding angles are congruent.
10. <PBD is congruent to <IBC - Reflexive property
11. Triangle BDP is similar to triangle BCI- Angle Angle similarity postulate
12. DB/CB=PD/CI- Corresponding sides of similar triangles are proportionate
13. <PCD is congruent to <HCB - Reflexive property
14. <CPD is congruent to <CHB - When two parallel lines are cut by a transversal, Corresponding angles are congruent.
15. Triangle PCD is similar to triangle HCB- Angle Angle similarity postulate
16. PD/HB=CD/BC -Corresponding sides of similar triangles are proportionate
17. (PD)(BC)=(HB)(CD) - Cross multiplication from line 16
18. (DB)(CI)=(BC)(PD) - Cross multiplication from line 12
19. BH=((AP)(BF))/(AF) - Multiplication and division from line 8
20. CI = ((AP)(EC))/(AE) - Multiplication and division from line 4
21. (PD)(BC)= ((AP)(BF)(CD)) / (AF) - Substitution lines 17 and 19
22. ((DB)(AP)(EC)) / (AE) = (PD)(BC) substitution lines 18 and 20
23. ((AP)(BF)(CD)) / (AF) = ((DB)(AP)(EC)) / (AE) Reflexive-lns 21 & 22
24. (AE)(AP)(BF)(CD) = (AF)(DB)(AP)(EC) - Multiply both sides by (AF)(AE)
25. (AE)(BF)(CD)=(AF)(DB)(EC) -Divide both sides by (AP)