(48) Shoelace Method For Determining A Polygon's Area - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Software Libraries (/forum-10.html) +--- Forum: General Software Library (/forum-13.html) +--- Thread: (48) Shoelace Method For Determining A Polygon's Area (/thread-11048.html) (48) Shoelace Method For Determining A Polygon's Area - gerry_in_polo - 07-14-2018 03:12 AM Shoelace Method for determining the area enclosed by any polygon. Enter the (X,Y) coordinates of the N polygon corners in a 2xN matrix and run the program. Example enter the following matrix of (X,Y) coordinates: [[2 5] [7 10] [12 20] [8 12] [4 3]] The polygon area calculated by the program is 10.5 RE: (48) Shoelace Method For Determining A Polygon's Area - Thomas Klemm - 07-14-2018 09:39 AM This program works as well for the HP-48: Code: ```\<<   DUP HEAD +   2 \<< CROSS \>> DOSUBS   \GSLIST ABS 2 / \>>``` However the pair of coordinates are expected in a list. Example: { [ 2 5 ] [ 7 10 ] [ 12 20 ] [ 8 12 ] [ 4 3 ] } Area = 10.5