Step-by-step explanation:
In the given circle
[tex] BC \cong BD [/tex] (Radii of same circle)
[tex] \angle BDC \cong \angle BCD.... (1)\\[/tex]
(angles opposite to congruent sides are congruent)
[tex] \angle ABC[/tex] is exterior angle of [tex] \triangle BDC[/tex]
[tex] m\angle ABC= m\angle BDC +m\angle BCD\\
\therefore 124°= m\angle BDC+m\angle BDC\\.. [from\:(1)] \\
\therefore 124°= 2m\angle BDC\\\\
\therefore m\angle BDC= \frac{124°}{2}\\\\
\therefore m\angle BDC= 62°\\
\huge \pink {\boxed {\therefore m\angle ADC= 62°}} \\.. (\because A-B-D) \\
[/tex]
