Explanation:
The way that I would do it, would be to use the point distance formula to find the length of each side.
Distance formula:
After you use this formula to find the length of all sides of the polygon, you would need to use the appropriate area formula to find the area of the polygon.
Area of Triangle: A= 1/2 base times height
Area of Rectangle: A= length times width
Area of Square: A= s^2 where s is the length of the side
Area of Parallelogram: A= base times height
Area of Trapezoid: A= 1/2 times height (base 1 + base 2) where base 1 and base 2 are the parallel sides
Area of Kite or Rhombus: A= 1/2 (diagonal 1 times diagonal 2)
Area of Regular Polygons: A= 1/2 (apothem times perimeter)