Given: Rhombus ABCD with diagonal AC To prove: ACF bisects ∠BAD and ∠BCD1. AB ≅ CD 1. opposite sides of a parallelogram are congruent 2. BC ≅ AD 2. opposite sides of a parallelogram are congruent 3. AC ≅ AC 3. a line is congruent to itself. 4. ΔABC ≅ ΔADC 4. SSS 1,2,3 5. ∠1 ≅ ∠4 5. corresponding parts of congruent triangles. 6. ∠3 ≅ ∠2 6. corresponding parts of congruent triangles. 7. AB ≅ BC 7. definition of rhombus, all sides congruent. 8. ΔABC is isosceles 8. two sides congruent, 7 9. ∠1 ≅ ∠3 9. base angles of an isosceles triangle 10. ∠1 ≅ ∠2 10. things congruent to the same thing are equal to each other, 6,9 11. AC bisects ∠ABD 11. from 10 12. ∠3 ≅ ∠4 12. things congruent to the same thing are equal to each other, 5,9 13. AC bisects ∠BCD 13. from 12 Edwin