two outer angle are not equal

two outer angle are not equal

i want to know one thing are two outer angle of triangle different from
each other?let us consider following problem
n the figure above, $AD = AC = CB.$ If the value of $y$ is $28$, what is
the value of $x$?

i have calculated angles and got that angle $ACD=ADC=56$,so angle $x$
should equal to angles $112$,but maybe i missed something and not include
angle $DAC$ and angle $BAC$ in calculation,just suppose that $x$ ax
external angle is equal to angle $ADC$+$ACD$,so which one is
correct?please help me