What is the first action the music teacher should take upon learning of Angel's abuse?

The first action the music teacher should take upon learning of Angel's abuse is to report directly to ChildLine. This is because ChildLine is the designated state agency responsible for receiving and investigating reports of child abuse in Pennsylvania. According to the law, mandated reporters, such as educators, have a legal obligation to report suspected child abuse immediately to the appropriate agency, which in this case is ChildLine.

By reporting directly to ChildLine, the music teacher ensures that trained professionals evaluate the situation, provide necessary intervention, and initiate an investigation. It is crucial for mandated reporters to act quickly and appropriately to protect the child without taking actions that might compromise an investigation or further endanger the child.

Reporting to the school principal, confronting the mother's boyfriend, or contacting the police may not be the appropriate first actions because they could delay the reporting process or interfere with the proper investigation and protocol established by child welfare agencies.