在梯形ABCD中,AD//BC,AB垂直AC.角B=45度,AD=根号2,BC=根号32,求DC的长
问题描述:
在梯形ABCD中,AD//BC,AB垂直AC.角B=45度,AD=根号2,BC=根号32,求DC的长
答
过A做AE⊥BC,交BC于E,过D做DF⊥BC,交BC于F∵∠B = 45° ,AC⊥AB∴△ABC是等腰Rt△∵AE⊥BC∴E是BC的中点,AE = BE =EC = BC/2 = 2√2∵AD//BC,Ae⊥BC,DF⊥BC∴DF = AE = 2√2EF = AD = √2∴CF = CE-EF=√2∴在Rt△DF...