Answer:
I'm not sure what you're trying to find, so I went ahead and wrote you a proof.
Step-by-step explanation:
BA ≅ BC - Given
AD ≅ DC - Definition of a midpoint
∠ABD ≅ ∠CBD - Given
BD ≅ DB - Reflexive property of ≅
∠DAB ≅ ∠DCB - ASA
y = 6
x = 40
