Find the following squares using one of the above identities.
\(1. (a+b)^2 = a^2 + 2ab + b^2\)
\(2. (a-b)^2 =a^2 - 2ab + b^2\)
\(3. (a+b+c)^2 = a^2 + b^2 + c^2 + 2ab + 2bc + 2ca\)
Determine which of these identities will make these calculations easier.
\(198^2\)