Proofs:

 

Note to Angle Sigma:

 

 

***************

 

Proof 1:  Angle Sigma

 

 

***************

 

Proof 2: Collinearity of points Pa, Pb, Pc and G

 

This proof is independent of angle φ = φa = φb = φc (cf. Fig. 08 of the website)

and is therefore also valid for the theorem with  common tangents to the McCay circles!

 

********************************************

 

Proof 3: After the Affine Transformation the Angle  ε = 45°

 

 

***************

 

Proof 4: 

 

inscribed angle, angle bisector
two circles of Apollonius

 

***************

 

Proof 5: 

 

Apollonius' circle, McCay circles

 

********************************************

 

Proof 6:

... that the c-McCay circle is also the G-Apollonius circle of line segment McCbr:

 

... see proof 3.

 

 

[back]