\(G\left( {\dfrac{{{x_A} + {x_B} + {x_C}}}{3};\dfrac{{{y_A} + {y_B} + {y_C}}}{3};\dfrac{{{z_A} + {z_B} + {z_C}}}{3}} \right)\)

\(G\left( {\dfrac{{{x_A} + {x_B} + {x_C}}}{4};\dfrac{{{y_A} + {y_B} + {y_C}}}{4};\dfrac{{{z_A} + {z_B} + {z_C}}}{4}} \right)\)

\(G\left( {\dfrac{{{x_A} - {x_B} + {x_C}}}{3};\dfrac{{{y_A} - {y_B} + {y_C}}}{3};\dfrac{{{z_A} - {z_B} + {z_C}}}{3}} \right)\)  

\(G\left( {\dfrac{{{x_A} - {x_B} - {x_C}}}{3};\dfrac{{{y_A} - {y_B} - {y_C}}}{3};\dfrac{{{z_A} - {z_B} - {z_C}}}{3}} \right)\)