One important use of coordinates is to communicate geometric information precisely. Like an address in a city, they tell you exactly where to go. Because the plane is laid out in a grid, these “addresses” are simple, consisting of 2 signed numbers. 

Consider a quadrilateral $ABCD$ in the coordinate plane. Performing a dilation of $ABCD$ requires 3 vital pieces of information:

1. The coordinates of $A$, $B$, $C$, and $D$

2. The coordinates of the center of dilation

3. The scale factor 

With this information, we can dilate each of the vertices $A$, $B$, $C$, and $D$ and then draw the corresponding segments to find the dilation of $ABCD$. Without coordinates, describing the location of the new points would likely require sharing a picture of the polygon and the center of dilation.