Answer:
1. Given
2. Base angle of isosceles triangle
3. ∡ACB and ∡ ACD are rt. angle
4. From statement 2 or Definition of right angled triangle
5. ASA axiom
6. BC ≅ CD
7. AC bisects BD( From statement 6 and property of bisector
Explanation:
Given: Isosceles ΔABD with AB ≅ AD; AC ⊥BD
Prove: AC bisects BD.
Statements (Reason in bracket)
1. Isosceles ΔABD with AB ≅ AD; AC ⊥BD (Given)
2. ∡B ≅ ∡D (Base angle of isosceles triangle)
3. ∡ACB and ∡ ACD are rt. angle (Definition of ⊥ lines)
4. ΔACB ≅ ΔACD are rt. Δs. (From statement 2 or Definition of right angled triangle)
5. ∴ ΔACB ≅ ΔACB. (ASA axiom)
Note: Here may be RHS axiom of congruency but one side is not given, so i used ASA axiom of congruence)
6. BC ≅ CD (CPCTC)
7. ∴ AC bisects BD( From statement 6 and property of bisector)
