锟斤拷锟斤拷省锟竭帮拷锟斤拷锟斤拷锟2017-2018锟絎锟斤拷劝锟斤拷昙夛拷碌锟揭伙拷锟斤拷驴锟斤拷锟斤拷W試锟斤拷锟斤拷锟斤拷 锟斤拷锟斤拷锟斤拷锟斤拷锟絵锟斤拷計12锟街o拷 23.锟斤拷D, 锟絚E锟角撅拷锟斤拷ABCD锟侥岋拷锟角撅拷BD锟较碉拷一锟絚, 锟斤拷BE=BC, AB=3, BC=4, 锟絚P锟斤拷直锟斤拷EC锟较碉拷一锟絚, 锟斤拷PQ锟斤拷BC锟斤拷锟絚Q, PR锟斤拷BD锟斤拷锟絚R. 锟斤拷1锟斤拷锟斤拷D1, 锟斤拷锟絚P锟介線锟斤拷EC锟斤拷锟絚锟絩, 锟斤拷锟斤拷PR+PQ=_____锟斤拷 锟斤拷2锟斤拷锟斤拷D2, 锟斤拷锟絚P锟介線锟斤拷EC锟较碉拷锟斤拷锟斤拷一锟絚锟斤拷锟斤拷锟絚锟絚E锟斤拷锟絚C锟截合o拷锟絩, 锟斤拷锟斤拷锟絣锟斤拷锟斤拷變, 锟絫锟斤拷1锟斤拷锟叫的結論锟角凤拷锟斤拷然锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷, 請锟給锟斤拷锟紺锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷, 請锟絝锟斤拷锟斤拷锟斤拷. 锟斤拷3锟斤拷锟斤拷D3, 锟斤拷锟絚P锟介線锟斤拷EC锟斤拷锟絃锟斤拷锟较碉拷锟斤拷锟斤拷一锟絚锟絩, 锟斤拷锟斤拷锟絣锟斤拷锟斤拷變, 锟絫PR锟絚PQ之锟絞锟街撅拷锟斤拷锟斤拷锟接的旓拷锟斤拷锟絇系锟斤拷請锟紺锟斤拷锟斤拷牟锟斤拷锟锟斤拷
|