# Animation for smoothly connected biarcs
Let(A=[0,0], D=[u1,0], B=[u2,u3], M=[X,Y], C1=[0,x1], C2=[x2,x3], I2=[x6,x7]):
BiarcA := Theorem([perpendicular(B,C2,B,D), oncirc(C1,A,M),
                   oncirc(C2,B,M), online(C1,C2,M),
                   u1+t-2*x6, u1*u2-u1^2+t^2-u2*t-2*u3*x7,
                   u3^2+(u1-u2)^2-t^2, circumcenter(A,B,M,I2)],
                  parallel(A,D,A,D), [t,Y,x1,x2,x3,x6,x7]);
Remark(
`See D. Wang: Elimination Methods. Springer, Wien New York (2001) 209-211.` 
):
