What is the first error Alycia made in her proof.

Answer: Alycia only established some of the necessary conditions for a congruence criterion.
Step-by-step explanation: Two triangles are congruent if their corresponding sides or/and corresponding angles are the same.
There are 5 ways to find out if the triangles are congruent.
The one Alycia used seems to be the one called Side-Angle-Side, which states that if two sides and its included angle is equal to the corresponding sides and angle of the other triangle, they are congruent.
For triangles ΔOPQ and ΔSTR to be congruent, using that theorem:
1) ∠O = ∠S
2) OP = TS
And
3) RS = OQ
So, Alycia's error is that she didn't prove RS = OQ, which would definitively conclude that both triangles are congruent.