Finding smartphone position

I have 3beacon’s .
Using android smartphone I am able to scan beacon’s and able to get RSSI,Txpower values.
Using d = 10 ^ ((TxPower - RSSI) / (10 * n)) formula to calculate distance btwn phone and beacon.
All 3 Beacon’s mTxPowerLevel is 8dbm.
I have Raspberry Pi attached so Now I want to find the position of my android phone.Is there any way to find position?