Answer:
∠ABD = 19.5°
∠ABE = 160.5°
Explanation:
Given angle ABC = 39° and its bisector BD, you want the measures of angle ABD and ABE, its supplement.
Angle bisector
An angle bisector divides an angle into two equal parts, each with half the measure of the whole.
∠ABD = 1/2∠ABC
∠ABD = 1/2(39°)
∠ABD = 19.5°
Linear pair
The angles of a linear pair are supplementary: they total 180°. Angles ABD and ABE form a linear pair.
∠ABE = 180° -∠ABD
∠ABE = 180° -19.5°
∠ABE = 160.5°