Pivot's Theorem
Pivot:=proc() local A,B,C,A1,B1,C1,t1,t2,t3,P1,P2:
A1:=[t1*B[1]+(1-t1)*C[1] , t1*B[2]+(1-t1)*C[2]]:
ConcurrentCes(
Ce(A,B1,C1) ,
Ce(B,A1,C1)
,
Ce(C,A1,B1) ):
end:
B1:=[t2*C[1]+(1-t2)*A[1] , t2*C[2]+(1-t2)*A[2]]:
C1:=[t3*A[1]+(1-t3)*B[1] , t3*A[2]+(1-t3)*B[2]]: