Answer:
= 9
Step-by-step explanation:
The given parameters are;
The point of intersection of the perpendicular bisectors of the sides
,
, and
intersect (meet) at point G
Let D represent the point of intersection of the perpendicular bisector from G to
, we have for ΔBGD and ΔCGD;
≅
by reflexive property
∠GDB = ∠GDC = 90° given that
is the perpendicular bisector of 
Similarly,
≅
, also given that
is the perpendicular bisector of 
Therefore;
ΔBGD ≅ ΔCGD by Side-Angle-Side (SAS) rule of congruency
≅
by Congruent Parts of Congruent Triangles are Congruent, (CPCTC)
=
= 9 by definition of congruency
∴
= 9.