△abc is an isosceles triangle with legs ab and ac. △ayx is also an isosceles triangle with legs ay and ax. the proof that △abc ~ △ayx is shown. statements reasons 1. △abc is isosceles with legs ab and ac; △ayx is also isosceles with legs ay and ax. 1. given 2. ab ≅ ac and ay ≅ ax 2. definition of isosceles triangle 3. ab = ac and ay = ax 3. definition of congruency 4. ay • ac = ax • ac 4. multiplication property of equality 5. ay • ac = ax • ab 5. substitution property of equality 6. 6. division property of equality 7. 7. division property of equality 8. ? 8. ? 9. △abc ~ △ayx 9. sas similarity theorem which statement and reason are missing in the proof? ∠a ≅ ∠a; reflexive property ∠x ≅ ∠x; reflexive property ∠abc ≅ ∠ayx; corresponding angles of similar triangles ∠abc ≅ ∠axy; corresponding angles of similar triangles