diff --git a/GDP/D3D9/Mesh.cpp b/GDP/D3D9/Mesh.cpp
index 7b6e54d..02238bf 100644
--- a/GDP/D3D9/Mesh.cpp
+++ b/GDP/D3D9/Mesh.cpp
@@ -24,10 +24,16 @@ void Mesh::render(IDirect3DDevice9* pD3DDevice)
     // 1. set mesh data
     pD3DDevice->SetStreamSource(0, _pVertexBuffer, 0, _vertexStride);
     pD3DDevice->SetFVF(FVF);
+    pD3DDevice->SetIndices(_pIndexBuffer);
 
     // 2. draw call
     // vertex buffer only 
-    pD3DDevice->DrawPrimitive(D3DPT_TRIANGLELIST, 0, _vertexCount / 3); 
+    //pD3DDevice->DrawPrimitive(D3DPT_TRIANGLELIST, 0, _vertexCount / 3);
+    //pD3DDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP, 0, _vertexCount - 2);
+    //pD3DDevice->DrawPrimitive(D3DPT_TRIANGLEFAN, 0, _vertexCount - 2);
+
+    // vertex & index buffer
+    pD3DDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, _vertexCount, 0, _indexCount / 3);
 }
 
 void Mesh::deInit()
@@ -39,7 +45,7 @@ void Mesh::deInit()
 UINT Mesh::createVertexBuffer(IDirect3DDevice9* pD3DDevice)
 {
     // 1. define mesh parameters
-    _vertexCount = 3;
+    _vertexCount = 4;
     _vertexStride = sizeof(Vertex);
 
     // 2. create vertex buffer object WITHOUT data
@@ -60,9 +66,31 @@ UINT Mesh::createVertexBuffer(IDirect3DDevice9* pD3DDevice)
     CheckFailed(hr, 310);
 
     // fill vertex buffer with data
-    pVertices[0] = Vertex(0.0f, 0.5f, 0.0f);
-    pVertices[1] = Vertex(0.5f, -0.5f, 0.0f);
-    pVertices[2] = Vertex(-0.5f, -0.5f, 0.0f);
+    //// triangle with triangle list
+    //pVertices[0] = Vertex(0.0f, 0.5f, 0.0f);
+    //pVertices[1] = Vertex(0.5f, -0.5f, 0.0f);
+    //pVertices[2] = Vertex(-0.5f, -0.5f, 0.0f);
+
+    // quad with triangle list, vertex buffer only
+    //pVertices[0] = Vertex(-0.5f, 0.5f, 0.0f);
+    //pVertices[1] = Vertex(0.5f, 0.5f, 0.0f);
+    //pVertices[2] = Vertex(0.5f, -0.5f, 0.0f);
+    //pVertices[3] = Vertex(-0.5f, 0.5f, 0.0f);
+    //pVertices[4] = Vertex(0.5f, -0.5f, 0.0f);
+    //pVertices[5] = Vertex(-0.5f, -0.5f, 0.0f);
+
+    //// quad with triangle strip, vertex buffer only
+    //pVertices[0] = Vertex(-0.5f, 0.5f, 0.0f);
+    //pVertices[1] = Vertex(0.5f, 0.5f, 0.0f);
+    //pVertices[2] = Vertex(-0.5f, -0.5f, 0.0f);
+    //pVertices[3] = Vertex(0.5f, -0.5f, 0.0f);
+
+    // quad with triangle fan, vertex buffer only
+    // quad with triangle list & index buffer
+    pVertices[0] = Vertex(-0.5f, 0.5f, 0.0f);
+    pVertices[1] = Vertex(0.5f, 0.5f, 0.0f);
+    pVertices[2] = Vertex(0.5f, -0.5f, 0.0f);
+    pVertices[3] = Vertex(-0.5f, -0.5f, 0.0f);
 
     hr = _pVertexBuffer->Unlock(); // transfer vertex buffer back from cpu memory to video memory
     CheckFailed(hr, 320);
@@ -74,5 +102,34 @@ UINT Mesh::createVertexBuffer(IDirect3DDevice9* pD3DDevice)
 
 UINT Mesh::createIndexBuffer(IDirect3DDevice9* pD3DDevice)
 {
+    _indexCount = 6; // triangle count * 3
+
+    HRESULT hr = pD3DDevice->CreateIndexBuffer(
+        _indexCount * sizeof(WORD),
+        D3DUSAGE_WRITEONLY,
+        D3DFMT_INDEX16,
+        D3DPOOL_MANAGED,
+        &_pIndexBuffer,
+        nullptr
+    );
+    CheckFailed(hr, 330);
+
+    WORD* pIndices = nullptr;
+
+    hr = _pIndexBuffer->Lock(0, 0, reinterpret_cast<void**>(&pIndices), 0);
+    CheckFailed(hr, 340);
+
+    // quad
+    // triangle 1 - 0, 1, 2
+    pIndices[0] = 0; pIndices[1] = 1; pIndices[2] = 2;
+
+    // triangle 2 - 0, 2, 3
+    pIndices[3] = 0; pIndices[4] = 2; pIndices[5] = 3;
+
+    hr = _pIndexBuffer->Unlock();
+    CheckFailed(hr, 350);
+
+    pIndices = nullptr;
+
     return 0;
 }
diff --git a/GDP/D3D9/main.cpp b/GDP/D3D9/main.cpp
index e94cea6..e41a168 100644
--- a/GDP/D3D9/main.cpp
+++ b/GDP/D3D9/main.cpp
@@ -36,6 +36,9 @@ int WINAPI WinMain(
 	error = d3d.init(window.getWindowHandle(), width, height, isFullscreen);
 	CheckError(error);
 
+	// set render states
+	d3d.getDevice()->SetRenderState(D3DRS_CULLMODE, D3DCULL_CCW);
+
 	// 3. create a mesh
 	Mesh mesh = {};
 	error = mesh.init(d3d.getDevice());