Answer:
Here is a proof
Angle DEF = angle ABC
A transversal cutting two parallel lines makes alternate exterior angles equal
Sum of measures of angles 1 and 2 = 50° + 48° = 98° = measure of angle DEF = measure of angle ABC
But since s bisects angle ABC, then angle 4 = 98 / 2 = 49°
But angles 3 and 4 are vertical angles....therefore.... measure of angle 3 = 49°
Step-by-step explanation:
