If a + b + c = 2s, then the value of (s - a)2 + (s - b)2 + (s - c)2 + s2 will be-

Answer: Option C

$$\begin{array}{rl}& {\left(s-a\right)}^2+{\left(s-b\right)}^2+{\left(s-c\right)}^2+s^2\\ & =\left(s^2+a^2-2sa\right)+\left(s^2+b^2-2sb\right)+\\ & \left(s^2+c^2-2sc\right)+s^2\\ & \\ & =4s^2+(a^2+b^2+c^2)-2s(a+b+c)\\ & =(2s{)}^2+(a^2+b^2+c^2)-\\ & (a+b+c)(a+b+c)\\ & =(a+b+c{)}^2+\left(a^2+b^2+c^2\right)-\\ & (a+b+c{)}^2\\ & =a^2+b^2+c^2\end{array}$$