If ≅ , ∠A ≅ ∠C, and bisects ∠ABC, which theorem or postulate can be used to prove △ABD ≅ △CBD?

The answer is a since the earth has different layers

Your answer is d. silli hope this ! : ) i left an explanation down below if you need it: a sill forms when hot magma squeezes between layers of rock to form a hardened sheet of rock. a sill is basically a tabular sheet intrusion between old layers of sedimentary rock, volcanic beds, or in the direction of foliation inherent in metamorphic rock. the word sill means a concordant intrusive sheet.