[tex]\begin{gathered} \text{Let's the width of the rectangle is }x. \\ Perimeter\text{ of rectangle is,} \\ \text{perimeter}=2(x+4) \\ \text{Area of rectangle is,} \\ \text{Area}=4x \\ \text{Now, perimeter and area both are equal,} \\ so, \\ 4x=2(x+4) \\ 4x=2x+8 \\ 4x-2x=8 \\ 2x=8 \\ x=4 \end{gathered}[/tex]
So, the width is also 4 unit.
