Problem 42699. Find the Area of a Polygon

Consider 2-D geometry and assume that the points are given in form of rows of a matrix. Find the area of polygon enclosed by the points.

Example:

A = [1 2;4 5; 6 7], represents points (1,2),(4,5) and (6,7)

Note :

1. There are no repeated rows in matrix.
2. There are at least 3 rows in matrix.
3. Coordinates in matrix are arranged in counter-clockwise direction.