Final answer:
To prove that triangle ABC is an isosceles triangle, we use the midpoint property and congruence of triangles.
Step-by-step explanation:
The given flowchart proof is about proving that triangle ABC is an isosceles triangle.
First, based on the given information, we know that D is the midpoint of AC, which means AD = DC.
Then, using CPCTC (Corresponding Parts of Congruent Triangles are Congruent), we can conclude that angle ADB = angle CDB.
Since AD = DC and angle ADB = angle CDB, we can conclude that triangle ADB is congruent to triangle CDB by SAS (Side-Angle-Side) congruence.
Therefore, AB = BC, proving that triangle ABC is an isosceles triangle.