diff --git a/src/Geometry.h b/src/Geometry.h
new file mode 100644
index 0000000..7f0b8b3
--- /dev/null
+++ b/src/Geometry.h
@@ -0,0 +1,30 @@
+#ifndef GEOMETRY_H_
+#define GEOMETRY_H_
+
+#include <Eigen/Core>
+
+using Eigen::Matrix4f;
+using Eigen::Vector3f;
+
+class Geometry {
+public:
+  enum class Type { SPHERE, RECTANGLE };
+
+  virtual ~Geometry() = default;
+
+protected:
+  Geometry(Type type, float ka, float kd, float ks, const Vector3f &ca,
+           const Vector3f &cd, const Vector3f &cs, float pc)
+      : type(type), ka(ka), kd(kd), ks(ks), ca(ca), cd(cd), cs(cs), phong(pc) {}
+
+  Type type;
+  float ka, kd, ks;    // coefficients for ambient, diffuse and specular
+  Vector3f ca, cd, cs; // ambient, diffuse and specular reflection color
+  float phong;         // phone coefficient, for `pc`
+  Matrix4f transform = Matrix4f::Identity();
+
+public:
+  void setTransform(const Matrix4f &);
+};
+
+#endif // !GEOMETRY_H_