12
解析分析:根據(jù)圖形,先找出單個(gè)的角組成的對(duì)頂角是4對(duì),再找出兩個(gè)角組成一個(gè)角而組成的對(duì)頂角是4對(duì),三個(gè)角組成一個(gè)角組成的對(duì)頂角是4對(duì),最后加在一起即可.
解答:如圖,單個(gè)角組成的對(duì)頂角有4對(duì),
兩個(gè)角看做一個(gè)角組成的對(duì)頂角有4對(duì),
三個(gè)角看做一個(gè)角組成的對(duì)頂角有4對(duì),
所以對(duì)頂角共有4×3=12對(duì).
故應(yīng)填12.
點(diǎn)評(píng):本題是規(guī)律探尋題,按順序找出各自情況的對(duì)頂角的對(duì)數(shù)是正確解題的關(guān)鍵.