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as AM is to MC,
so is the triangle ABM to MBC, and
AME to EMC;
for they are to one another as their bases. [VI.1]
Therefore also,
as one of the antecedents is to one of the consequents, so are all the antecedents to all the consequents; [V.12]
therefore
as the triangle AMB is to BMC,
so is ABE to CBE.
