Tyne and Wear is one of six metropolitan counties in England, comprising the estuary areas of the rivers Tyne and Wear[?]. It is divided into the following council areas: South Tyneside, North Tyneside, Newcastle-upon-Tyne, Gateshead and Sunderland. It borders on County Durham and Northumberland.
... Generalizations
The formula and its proof remain correct if the coefficients a, b and c are complex numbers, or more generally members of any field ...