we know that
Vertical angles are congruent angles
that means
substitute the given values
(7x – 27)=(3x + 29)
solve for x
7x-3x=29+27
4x=56
x=14
part b)
We know that
Supplementary angles are angles that their sum is equal to 180 degrees
so
A+B=180
substitute the given values
5x+25+x+17=180
solve for x
6x+42=180
6x=180-42
6x=138
x=23
Find the measure of Angle A