C is the incenter of isosceles triangle ABD with vertex angle
ABD. Does the following proof correctly justity that triangles ABC and DBC are congruent?
1. It is given that is the incenter of triangle ABD, so segment BC is an altitude of angle ABD.
2. Angles ABC and DBC are congruent according to the definition of an angle bisector
3. Segments AB and DB are congruent by the definition of an isosceles triangle
4. Triangles ABC and DBC share side BC, so it is congruent to itself by the reflexive property
5. By the SAS postulate, triangles ABC and DBC are congruent
There is an error in line 1. segment BC should be an angle bisector,
The proot is correct
There is an error in line 3. segments AB and BC are congruent
Theresantno in ne 5, the ASA Postulate should be used