ComputeCodes

easy to use polygon area calculator with example.

Area of polygon when the coordinates of its vertices are known uses Coordinate Geometry formula. https://www.mathopenref.com/coordpolygonarea.html. This method will produce the wrong answer for self-intersecting polygons, where one side crosses over another, as shown on the right. It will work correctly however for triangles, regular and irregular polygons, convex or concave polygons.