Question

what is the congruence statement for the given triangles?
△adc≅△adb
△adc≅△abc
△adc≅△adc
△adc≅△cda

Explanation:

Step1: Identify congruent parts

We see $AD = AD$ (common side), $CD=BD$ (marked with equal - length dashes), $\angle ADC=\angle ADB$ (marked with same - angle arcs).

Step2: Determine congruence statement

By Side - Angle - Side (SAS) congruence criterion, $\triangle ADC$ and $\triangle ADB$ are congruent.

Answer:

$\triangle ADC\cong\triangle ADB$