package gx import ( "math" ) // The structure of a triangle. What more you want to hear? type Triangle [3]Point type Triangles []Triangle // Returns the area of the triangle. func (t Triangle) Area() Float { x1 := t[0].X y1 := t[0].Y x2 := t[1].X y2 := t[1].Y x3 := t[2].X y3 := t[2].Y return math.Abs( (x1*(y2-y3) + x2*(y3-y1) + x3*(y1-y2))/2) }