How do you use coordinates to find the perimeter and area of polygons?

Step-by-step explanation:

Make a table with the x,y coordinates of each vertex.

Vertical left side of the table  A ,B,C D.. A again (From top to bottom)

Horizontal top of the table : x,y(  From left to right)

Start at any vertex and go around the polygon in either direction.

Add the starting vertex again at the end.

Combine the first two rows by:

Multiplying the first row x by the second row y

Multiplying the first row y by the second row x

Subtract the second product form the first.

Repeat this for rows 2 and 3, then rows 3 and 4 and so on.

Add these results, make it positive if required, and divide by two.