Proof: Converse of Parallel Lines 4     
line ABCD
ECD = 140
ABF = 40
line BF line CE
1. 
1. 
ABC = ABF + FBC
140 = FBC
ABC = 180
FBC + BCE = FBC + BCE
FBC + BCE = 140 + 40; FBC + BCE = 180
180 = 40 + FBC
180 = BCE + 140
40 = BCE
BCD = 180
ECD = 140
line ABCD
FBC = FBC
ABF = 40
BCD = BCE + ECD
line BF line CE
FBC and BCE are supplementary



ProveIt! by Michael Ferraro <mferraro@balstaff.org>.
Copyright ©2010. All rights reserved.