Question

the proof that \\( \triangle acb \cong \triangle ecd \\) is shown.\
given: \\( ac \\) and \\( db \\) intersect each other at \\( c \\).\
prove: \\( \triangle acb \cong \triangle ecd \\)\
what is the missing statement in the proof?\
\\( \bigcirc \\) \\( \angle bac \cong \angle dec \\)\
\\( \bigcirc \\) \\( \angle acd \cong \angle ecb \\)\
\\( \bigcirc \\) \\( \angle acb \cong \angle ecd \\)\
\\( \bigcirc \\) \\( \angle bca \cong \angle dca \\)

Explanation:

To prove $\triangle ACB \cong \triangle ECD$ with the given that $AE$ and $DB$ intersect at $C$, we need a pair of congruent vertical angles formed by the intersecting lines. Vertical angles created by intersecting lines are congruent, and $\angle ACB$ and $\angle ECD$ are vertical angles here.

Answer:

$\boldsymbol{\angle ACB \cong \angle ECD}$