Given: AD bisects ∠ CAB, AD > BD

Prove: AC > DC

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AC > DC
The exterior angle theorem
∠ 4 > ∠ 1
Substitution
∠ 1 = ∠ 2
∠ 4 > ∠ 2
AD bisects ∠ CAB, AD > BD
If two angles of a triangle are unequal, the sides opposite them are unequal in the same order
Given
Definition