\(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfKttLearuGlw5gvP1wzaeXatLxBI9gBam % XvP5wqSXMqHnxAJn0BKvguHDwzZbqegm0B1jxALjhiov2DaeHbuLwB % Lnhiov2DGi1BTfMBaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFf % euY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9 % q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGacaGaaeqaba % WaaqaafaaakqaabeqaaabaaaaaaaaapeWaaiqaaqaabeqaaiabdIha % 4jabdMha5jabc+caViabc+caViabdQha6jabdsha0bqaamaaHaaaba % GaemyEaKNaemyqaeKaemOqaieacaGLcmaacqWG2bGDcqWGHbqydaqi % aaqaaiabdgeabjabdkeacjabdsha0bGaayPadaGaemiDaqNaemOCai % Naem4Ba8MaemOBa4Maem4zaCgaaiaawUhaaaqaaiabgkDiEpaaHaaa % baGaemyEaKNaemyqaeKaemOqaieacaGLcmaacqGHRaWkdaqiaaqaai % abdgeabjabdkeacjabdsha0bGaayPadaGaeyypa0JaeGymaeJaeGio % aGJaeGimaaZaaWbaaSqabeaacqaIWaamaaaakeaacqGHshI3daqiaa % qaaiabdgeabjabdkeacjabdsha0bGaayPadaGaeyypa0JaeGymaeJa % eGioaGJaeGimaaZaaWbaaSqabeaacqaIWaamaaGccqGHsisldaqiaa % qaaiabdMha5jabdgeabjabdkeacbGaayPadaGaeyypa0JaeGymaeJa % eGioaGJaeGimaaZaaWbaaSqabeaacqaIWaamaaGccqGHsislcqaIXa % qmcqaIXaqmcqaIWaamdaahaaWcbeqaaiabicdaWaaakiabg2da9iab % iEda3iabicdaWmaaCaaaleqabaGaeGimaadaaaaaaa!861D! \begin{array}{l} \left\{ \begin{array}{l} xy//zt\\ \widehat {yAB}\,\,và\,\,\widehat {ABt}\text{ nằm ở vị trí trong cùng phía } \end{array} \right.\\ \Rightarrow \widehat {yAB} + \widehat {ABt} = {180^0}\\ \Rightarrow \widehat {ABt} = {180^0} - \widehat {yAB} = {180^0} - {110^0} = {70^0} \end{array}\)

Lại có

\(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfKttLearuGlw5gvP1wzaeXatLxBI9gBam % XvP5wqSXMqHnxAJn0BKvguHDwzZbqegm0B1jxALjhiov2DaeHbuLwB % Lnhiov2DGi1BTfMBaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFf % euY-Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9 % q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGacaGaaeqaba % Waaqaafaaakqaabeaeaaaaaaaaa8qabaWaaecaaeaacqWG6bGEcqWG % cbGqcqWG2bGDaiaawkWaaiabdAha2jabdggaHnaaHaaabaGaemyqae % KaemOqaiKaemiDaqhacaGLcmaaaeaadaqiaaqaaiabdQha6jabdkea % cjabdAha2bGaayPadaGaeyypa0ZaaecaaeaacqWGbbqqcqWGcbGqcq % WG0baDaiaawkWaaiabg2da9iabiEda3iabicdaWmaaCaaaleqabaGa % eGimaadaaaaaaa!550C! \begin{array}{l} \widehat {zBv}\,\,và\,\,\widehat {ABt}\text{ đối đỉnh}\\ \Rightarrow\widehat {zBv} = \widehat {ABt} = {70^0} \end{array}\)