# Math Help - Proof

1. ## Proof

Given: A-B-C, D is not on line AC so BD > CD.

2. Originally Posted by GoldendoodleMom
Given: A-B-C, D is not on line AC so BD > CD.
$\angle C > \angle CBD$ If one side of a triangle (BD) is longer than another side (CD), then the angle opposite the longer side has a greater measure than the angle opposite the shorter side.
$\angle ABD > \angle C$ If an angle is an exterior angle of a triangle, then its measure is greater than either of its corresponding remote interior angles.
$\therefore AD > BD$ If one angle of a triangle ( $\angle ABD$) has a greater measure than another angle, then the side opposite the greater angle is longer than the side opposite the lesser angle ( $\angle C$).