Comment on Atticus' explanation of rape. why does Atticus explain the crime in this way ?

Scout candidly asks Atticus what rape is. To this question, he sighs, and calmly responds in the way that only Atticus can. He says that it is "carnal knowledge of a female by force and without consent." Atticus never belittles his children. He explains to Scout what she needs to know and is there for any questions. Scout and Jem are both comfortable with asking their dad almost anything.