Respuesta :
if the figure is indeed a triangle, TRI=3, it means is a polygon with 3 sides, so one can safely assume that.
Answer:
Assume that the figure does not have three sides.
Step-by-step explanation:
I think that "indirectly" can be a demostration by contradiction. In that case, the first step would be and false assumption about triangles. That is, Assume that the figure does not have three sides.