Using the ASA congruence theorem, the missing statement in her proof is: A. ΔACD ≅ ΔECB.
Two triangles are congruent by the ASA congruence theorem if they have two pairs of corresponding congruent angles and a pair of included congruent sides.
In the proof given in the diagram, using the ASA congruence theorem, Rowena has been able to prove that ΔACD and ΔECB have two pairs of corresponding congruent angles and a pair of included congruent sides.
Therefore, the missing statement in her proof is: A. ΔACD ≅ ΔECB.
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