diff --git a/src/cmd/math/main.go b/src/cmd/math/main.go
index f6fc777..645bfe5 100644
--- a/src/cmd/math/main.go
+++ b/src/cmd/math/main.go
@@ -6,69 +6,16 @@ import (
 )
 
 func main() {
-	lines := []gx.Line{
-		gx.LineSegment{
-			gx.Point{0, 1},
-			gx.Point{1, 2},
-		}.Line(),
-		gx.LineSegment{
-			gx.Point{0, 5},
-			gx.Point{1, 2},
-		}.Line(),
-		gx.LineSegment{
-			gx.Point{-1, -1},
-			gx.Point{1, 50},
-		}.Line(),
-	}
-	
-	
-	for _, l := range lines { fmt.Println(l) }
-	
-	l1 := gx.LineSegment{
-		gx.Point{0, 0},
-		gx.Point{1, 1},
-	}.Line()
-	
-	l2 := gx.LineSegment{
-		gx.Point{0, 1},
-		gx.Point{1, 0},
-	}.Line()
-	
-	fmt.Println(gx.LinersCross(l1, l2))
-	fmt.Println(l1.ContainsPoint(gx.Point{1, 4}))
-	angle := gx.LinersAngle(l1, l2)
-	fmt.Println("angle:", angle, gx.RadiansToDegrees(angle))
-	
-	
-	t := gx.Rectangle{
-		Transform: gx.Transform{
-			S: gx.Vector{100, 200},
-			P: gx.Point{0, 200},
-			RA: gx.Point{0, 0},
-			R: 0,
-		},
-	}
-	
-	points := []gx.Point{
-		gx.Point{},
-		gx.Point{100, 0},
-		gx.Point{0, 99},
-		gx.Point{.1, .1},
-		gx.Point{-1, -1},
-		gx.Point{1, 1},
-		gx.Point{101, 1},
-		gx.Point{100, 1},
-		gx.Point{50, 1},
-	}
-	
-	ts := t.Triangles()
-	t1 := ts[0]
-	t2 := ts[1]
-	fmt.Printf("Rectangle triangles:\n\t%v\n\t%v\n", t1, t2)
-	for _, p := range points {
-		fmt.Println(p, t.ContainsPoint(p))
+	p := gx.Polygon{
+		gx.Vertex{0, 0},
+		gx.Vertex{0, 50},
+		gx.Vertex{25, 50},
+		gx.Vertex{30, 40},
+		gx.Vertex{40, 30},
 	}
 	
+	fmt.Println("barycenter:", p.Barycenter())
+	fmt.Println("edges:", p.Edges())
 }
 
 
diff --git a/src/gx/polygon.go b/src/gx/polygon.go
index 154060e..e9ad719 100644
--- a/src/gx/polygon.go
+++ b/src/gx/polygon.go
@@ -5,12 +5,79 @@ package gx
 // Should split it somehow.
 type Polygon []Point
 
+// Returns slice of edges.
 func (p Polygon) Edges() Edges {
 	ret := Edges{}
-	/*for i := range p {
-		ret = append(ret, Edge{})
-	}*/
+	
+	l := p.Len()
+	for i := range p {
+		ret = append(ret, Edge{p[i], p[(i+1)%l]})
+	}
 	
 	return ret
 }
 
+func (p Polygon) Len() int {
+	return len(p)
+}
+
+func (p Polygon) Vertices() []Vertex {
+	return p
+}
+
+func (p Polygon) Barycenter() Point {
+	ret := Point{}
+	for _, v := range p {
+		ret.X += v.X
+		ret.Y += v.Y
+	}
+	
+	l := Float(len(p))
+	ret.X /= l
+	ret.Y /= l
+	
+	return ret
+}
+
+/*
+func (p Polygon) anyPointInside() Point {
+	edges := p.Edges()
+	for _, e := range edges {
+		if
+	}
+}
+*/
+
+func (p Polygon) Triangles() Triangles {
+	/*
+	if len(p) < 3 {
+		return Triangles{}
+	} else 	
+	vertices = p.Vertices()
+	ret := Triangles{}
+	
+	i := 0
+	for len(vertices) != 3{
+
+		i1 = i % len(vertices)
+		i2 = (i+1) % len(vertices)
+		i3 = (i+2) % len(vertices)
+		
+		l1 = LineSegment{vertices[i1], vertices[i2]}.Line()
+		l2 = LineSegment{vertices[i1], vertices[i3]}.Line()
+		
+		if l1.K > 0 {
+			if l1.K 
+		} else {
+		}
+	}
+	
+	return append(
+		ret,
+		Triangle{p[0], p[1], p[2]},
+	)
+	*/
+	
+	return Triangles{}
+}
+
diff --git a/src/gx/vector.go b/src/gx/vector.go
index 3c658bc..d807ceb 100644
--- a/src/gx/vector.go
+++ b/src/gx/vector.go
@@ -22,6 +22,10 @@ func V(x, y Float) Vector {
 	return Vector{x, y}
 }
 
+func (v Vector) Eq(o Vector) bool {
+	return v.X == o.X && v.Y == o.Y
+}
+
 // Returns the vector with the matrix applied
 func (v Vector) Apply(m *Matrix) Vector {
 	x, y := m.Apply(v.X, v.Y)