<P style="TEXT-ALIGN: justify; LINE-HEIGHT: 21px; TEXT-INDENT: 0px; MARGIN: 0px; FONT-FAMILY: '한컴바탕'; COLOR: #000000; FONT-SIZE: 13px"><img onLoad='miniSelfResize(contents_376,this); if(this.parentNode.tagName=="A"){this.onclick = "";}' src="/shop/lib/meditor/../../data/editor/1327556960.jpg"> </P> <P style="TEXT-ALIGN: justify; LINE-HEIGHT: 21px; TEXT-INDENT: 0px; MARGIN: 0px; FONT-FAMILY: '한컴바탕'; COLOR: #000000; FONT-SIZE: 13px">정육면체 ABCD-EFGH에서 평면 BGD와 선분 CE가 수직으로 만난다</P> <P style="TEXT-ALIGN: justify; LINE-HEIGHT: 21px; TEXT-INDENT: 0px; MARGIN: 0px; FONT-FAMILY: '한컴바탕'; COLOR: #000000; FONT-SIZE: 13px">위 명제는 어떻게 증명하나요?</P>
