pg_geoext is a spatial extension prototype for teaching spatial database classes.

For more information read the doc

CREATE EXTENSION geoext;
SELECT geo_point_to_str('POINT (22.2 33.2);SRID = 4356'::geo_point)
SELECT 'POLYGON ((1 2),(12 6 ),(5 9),(1 2));SRID = 4556'::geo_polygon

• point(x,y)
• polygon((x1 y1), (x2 y3) .... (x1 y1))

geo_point_to_str();
geo_point_from_text();
geo_point_distance();

geo_polygon_area();
geo_polygon_perimeter();

The input and output of geo_point is hex