Respuesta :
First, number the vertices in order, going either clockwise or counter-clockwise, starting at any vertex.The area is then given by the formula. Where x1 is the x coordinate of vertex 1 and yn is the y coordinate of the nth vertex etc. Notice that the in the last term, the expression wraps around back to the first vertex again! Hope this helped.
Answer:
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.