Triangles IEB IEC are congruent (sides and included angle common)
The three lines are $ concurrent $ at E. $Three $ vertically opposite angles are same. Mark them separately as $ p,q,r $. Choose from among them conveniently .
BE = EC
Triangles AEI DEI are congruent (sides and included angle common)
Triangles IEB IEC are congruent (sides and included angle common)
The three lines are $ concurrent $ at E. $Three $ vertically opposite angles are same. Mark them separately as $ p,q,r $. Choose from among them conveniently .
BE = EC
Triangles AEI DEI are congruent (sides and included angle common)
DE = AE
Total chord length is same;
AE + EC = DE + EB.