Proof: Converse of Parallel Lines 3
line ABCD
ECD = 140
ABF = 40
line BF
line CE
1.
1.
ABC = 180
180
= 40
+
FBC
140
=
FBC
ABF = 40
line ABCD
line BF
line CE
ECD = 140
ABC =
ABF +
FBC
ProveIt!
by Michael Ferraro <
mferraro@balstaff.org
>.
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