\(\widehat{C_3}\) so lê trong \(\widehat{D_1}\)
\(\widehat{C_4}\) so le trong \(C_2\)
\(\widehat{C_3}\) đồng vị \(\widehat{D_3}\)
\(\widehat{C_2}\) đồng vị \(\widehat{D_2}\)
\(\widehat{C_1}\) đồng vị \(\widehat{D_1}\)
\(\widehat{C_3}\) trong cùng phía \(\widehat{D_2}\)
\(\widehat{C_4}\) trong cùng phía \(\widehat{D_1}\)