To solve this problem, we have to use this theorem
[tex]m\angle ADC=\frac{1}{2}m\angle\text{ABC}[/tex]
Replacing the given angle, we have
[tex]\begin{gathered} 23=\frac{1}{2}m\angle ABC \\ m\angle ABC=46 \end{gathered}[/tex]
Hence, the angle ABC is equal to 46°.
