There are several ways to silence the ringer before answering a call.
Method 1: Press the “Volume Down” or “Volume Up” or “Power” button to silence the ring.
Method 2: Go to menu -> “Settings” -> “Sound & vibration”-> activate “Silent mode”.
Method 3: Enter "Phone” app and pressing the menu key in the top right corner of the screen. Then go to “Settings” -> “Sounds and vibration” -> activate “Silent mode”.
Method 4: Drag the Status Bar down with your finger and then touch the “Media” icon to change to “Vibrate” or “Mute”.
Method 5: Enter the “Phone” app and press the menu key in the top right corner of the screen. Then go to “Settings” ->“Flip To Slience”->activate “Flip to Slience”, place your phone face down on a flat surface to silence an incoming call.
Note: Press the “power” key and “volume up” key at the same time to switch to vibration mode quickly.