A straight thin uniform rod of length 4L and mass 4M is bent into a square. Its M.I about one side is 

$$\begin{gathered} The length of each side is \frac{4L}{4}=L \\ Now each side has mass of\frac{ 4M}{4}=M \\ MI of side opposite to the axis is M{L}^2 \\ MI of side along the axis is 0 \\ MI of two sides adjacent to the axis is \frac{2\times M{L}^2 }{3}=\frac{2M{L}^2 }{3} \\ So total MI of the system is M{L}^2 +\frac{2M{L}^2}{3}=\frac{5M{L}^2}{3} \end{gathered}$$