# Shoelace formula for polygonal area

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This page is the answer to the task Shoelace formula for polygonal area in the Rosetta Code.

### Description (from Rosetta Code)

Given the `n + 1` vertices `x[0], y[0] .. x[N], y[N]` of a simple polygon described in a clockwise direction, then the polygon's area can be calculated by:
abs( (sum(x[0]*y[1] + ... x[n-1]*y[n]) + x[N]*y[0]) - (sum(x[1]*y[0] + ... x[n]*y[n-1]) + x[0]*y[N]) ) / 2 (Where
Write a function/method/routine to use the the Shoelace formula to calculate the area of the polygon described by the ordered points: (3,4), (5,11), (12,8), (9,5), and (5,6) |