Answer:
The measure angle ADB = 180 - (α/2+ β/2)
Step-by-step explanation:
measure angle A is α degrees, this means that, the angle bisector divides the angle into two equal angles each of measure α/2 degrees
measure angle B is β degrees, this means that the angle bisector divides the angle into two equal angles each of measure β/2 degrees
In triangle ADB, we know that the sum of all measure of a triangle is 180 degrees and we have measure angle MAB = α/2 degrees and measure angle MBA = β/2 degrees
Therefore,
measure angle ADB = 180 - (α/2+ β/2)