Let's recall that for finding the length of each side of the polygon, we can use the following formula:
![\text{ Distance or length of each side = }\sqrt{(x_{2\text{ }}}-x_1)^2+(y_{2\text{ }}-y_{1\text{ }})^2](https://img.qammunity.org/2023/formulas/mathematics/college/oj60z5tw9xyhaaj86t9cqfd1hkjghv84vv.png)
![\text{ Now, we can calculate the length of each side, as follows:}](https://img.qammunity.org/2023/formulas/mathematics/college/pktza8lmoyt4whssb5xl8xfxmpsjrarqmu.png)
The polygon given is REGULAR, so it will be easier to calculate the perimeter.
Side QR = 1 - (-3) = 1 + 3 = 4 (We use only the x values, because y is constant)
Side RS = 2 - -(2) = 2 + 2 = 4 (We use only the y values, because x is constant)
Side ST = 1 - (-3) = 1 + 3 = 4 (We use only the x values, because y is constant)
Side QT = 2 - (-2) = 2 + 2 = 4 (We use only the y values, because x is constant)
![\text{ Perimeter = 4 + 4 + 4 + 4 = 16 units}](https://img.qammunity.org/2023/formulas/mathematics/college/tdled5ls972lub6urznjuskiqoahwp58xv.png)