Help me please

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.

Determine which postulate or theorem can be used to prove that lmn =nmo

1. 2. ∠b and ∠y are right angles. 3.? 4.? which two statements are missing in steps 3 and 4? ∠x ≅ ∠c △abc ~ △zyx by the sas similarity theorem. ∠b ≅ ∠y △abc ~ △zyx by the sas similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem.