An easy way to prove the proof by direct proving is
1. states the given and reason it out as given
2. then you start the basic statement and reason.
3. you can support you answer by the postulate,definition and theorem .
4.just make it step by step.
like for example;
Given : AB ≈ BF , AC ≈CF
Prove : ΔABC ≈ Δ BCF
1.AB ≈BF GIVEN
3.BC≈CB REFLEXIVE PROPERTY OF EQUALITY
4.ΔABC≈ΔBCF BY SSS POSTULATE