Answering Calls on the Teams desktop app:
When someone calls you, you will get a notification at the bottom right of the screen.
Here you can select the phone icon for audio only or the camera for both audio and video.
Answering Calls on a physical Teams phone:
When someone calls you, your phone will ring and the display will change to show their caller information.
From here you can either pick-up the handset to begin the call, or press “Accept” to start the call in speaker mode.