diff -r 2bdc3ac5e77c -r 55a55a9ec2c2 src/objecttypes/polygon.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/objecttypes/polygon.h	Sun Sep 22 11:51:41 2019 +0300
@@ -0,0 +1,39 @@
+#include <array>
+#include "modelobject.h"
+
+namespace modelobjects
+{
+	class Triangle;
+	class Quadrilateral;
+}
+
+class modelobjects::Triangle : public ColoredBaseObject
+{
+public:
+	Triangle() = default;
+	Triangle(
+		const Vertex &point_1,
+		const Vertex &point_2,
+		const Vertex &point_3,
+		Color color_index = colors::main);
+	QVariant getProperty(Property id) const override;
+	SetPropertyResult setProperty(Property id, const QVariant& value) override;
+private:
+	Vertex points[3] = {{}};
+};
+
+class modelobjects::Quadrilateral : public ColoredBaseObject
+{
+public:
+	Quadrilateral() = default;
+	Quadrilateral(
+		const Vertex &point_1,
+		const Vertex &point_2,
+		const Vertex &point_3,
+		const Vertex &point_4,
+		Color color_index = colors::main);
+	QVariant getProperty(Property id) const override;
+	SetPropertyResult setProperty(Property id, const QVariant& value) override;
+private:
+	Vertex points[4] = {{}};
+};