I'm sorry to hear about your missing teacher. It's possible to track a phone live using its GPS signal, but it requires the phone to be turned on and have location services enabled. It's also important to note that tracking someone's phone without their consent is รฎllรฉgรขl and could result in serious consequences.
If you have access to the teacher's phone number or IMEI, you can contact the police and report the missing person. The police may be able to obtain a court order to track the phone's location through the service provider.
In the meantime, you can also try calling the missing teacher's phone or sending text messages to see if they respond. It's also a good idea to check with friends and family to see if they have any information on the teacher's whereabouts.