Question

I need help with segments​

Answer 1

∠ DBC = 16°

Explanation:

∠ ABD + ∠ DBC = ∠ ABC , substitute values

2x + 15 + x - 30 = 123 , that is

3x - 15 = 123 ( add 15 to both sides )

3x = 138 ( divide both sides by 3 )

x = 46

Thus

∠ DBC = x - 30 = 46 - 30 = 16°