m_a²  \; =  \;  \frac{ 2(b²+c²)-a² }{4 } \; \; 

m_b²  \; =  \;  \frac{ 2(a²+c²)-b² }{4 } \; \; 

m_c²  \; =  \;  \frac{ 2(a²+b²)-c² }{4 } 

A = (-0.1580772971305559, 1.1360859237541305)
B = (-0.9197086917245382, -0.20459399686678345)
C = (1.3338855717316285, -0.18894403670389343)
đa giác1, c, a_1, b = Polygon(A, B, C)
α = Angle(B, A, C)
M = Midpoint(a_1)
m_a = Segment(A, M)
a = Segment(B, M)
f = Segment(M, C)