Question

What is the value of X in the Figure

The numbers in the figure are 104° and {3x-19|°

Answer 1

yes they are both vertical, therefore equal, so set them equal and solve, as did "musiclover".
they are neither supplementary nor complementary.

Answer 2

both angles are equal so you have

104 = 3x-19

add 19 to both sides

123 = 3x

divide both sides by 3

x = 123/3

x = 41