Yes, ADC is congruent to ADC by HL Congruency and the legs that allow the use of HL are AC and BC
How to find the congruency postulate of the triangle?
There are different triangle congruency postulates such as:
SAS congruency postulate
SSS congruency postulate
ASA congruency postulate
AAS congruency postulate
HL congruency postulate
In this case, we see that:
BC ≅ CD
AC ≅ AC by reflexive property of congruence
∠ACB ≅ ∠ACD
Thus, the triangle is congruent by SAS Congruence postulate.
We also know that Corresponding parts of congruent triangles are congruent. Thus:
AB ≅ AC
Thus, the triangle can be congruent by HL Congruency