Problem 109:
Given a point $B$, a point $C$ and a point $M_{c}$, construct the triangle ABC.

Construction: 
1. Using the point $B$ and the point $M_{c}$, construct a point $A$ (rule W01);
2. Using the point $A$ and the point $B$, construct a point $\_M_{c}$ (rule W01);

Statement:
Prove that the point $B$ is identical to the point $B$.

