Finding $\angle ADC$ in $\triangle ABC$

[Albert1]

$\triangle ABC, \overline{AB}=\overline {AC}$,there exists an inner point ${D}$ and satisfyng :
(1)$\overline {AB}=\overline {AC}=\overline {BD}$
(2)$\angle DCB=30^o$
find $\angle ADC=?$

 

[Joppy]

Are these problems you need help with? Or are they just for members to try?

 

[Albert1]

Are these problems you need help with? Or are they just for members to try?

for members to try

 

[Albert1]

$\triangle ABC, \overline{AB}=\overline {AC}$,there exists an inner point ${D}$ and satisfyng :
(1)$\overline {AB}=\overline {AC}=\overline {BD}$
(2)$\angle DCB=30^o$
find $\angle ADC=?$

my solution

Spoiler

explanation :
GD//BC
let DE=GH=1,
EF=FH=x,
AK=y
$\angle DEC=\angle GHB=90^o$
Triangle AGD is an equilateral triangle

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