I have been following http://www.directxtutorial.com to learn d3d and i just finished the tutorial where awe make a triangle and i dont want to move on till i have this mastered so how can i modify this code to work. Thanks, Ignore the poor practices i am still learning

can you be more specific about what issue you are having? is the code not drawing anything, or is their another issue at play?

to me, it looks like you aren't copying the second triangle to the right address, and instead are overwriting the first:

 
v_buffer->Lock(0, 0, (void**)&pVoid, 0);
 
memcpy(pVoid, tri, sizeof(tri));
memcpy(pVoid, tri2, sizeof(tri2));
v_buffer->Unlock();

should be changed to:

 
v_buffer->Lock(0, 0, (void**)&pVoid, 0);
 
memcpy(pVoid, tri, sizeof(tri));
memcpy(pVoid+sizeof(tri), tri2, sizeof(tri2));
v_buffer->Unlock();

notice that the pVoid is now offset to the next triangle slot instead of overwritting the first slot(also notice the code tags, which can be used with: [*code] and [*/code](remove the *), to better format your code.)

alternatively you can also do:

void graphics()
{
 
CVERTEX tri[] = 
{
{SCREEN_WIDTH / 2, 100, 0.5f, 1.0f, D3DCOLOR_XRGB(0,0,255)},
{SCREEN_WIDTH / 2 + (SCREEN_WIDTH / 3), SCREEN_HEIGHT - 100, 0.5f,1.0f, D3DCOLOR_XRGB(0,255,0)},
{SCREEN_WIDTH / 2 - (SCREEN_WIDTH / 3), SCREEN_HEIGHT - 100, 0.5f,1.0f, D3DCOLOR_XRGB(255,0,0)},
{ 100, 100, 0.5f, 1.0f, D3DCOLOR_XRGB(0,0,255) },
{ 150, 150, 0.5f,1.0f, D3DCOLOR_XRGB(0,255,0) },
{ 50, 150, 0.5f,1.0f, D3DCOLOR_XRGB(255,0,0) }
};
 
 
d3ddev->CreateVertexBuffer(6 * sizeof(CVERTEX), 0, CFVF, D3DPOOL_MANAGED, &v_buffer, NULL);
void *pVoid;
 
v_buffer->Lock(0, 0, (void**)&pVoid, 0);
 
memcpy(pVoid, tri, sizeof(tri));
v_buffer->Unlock();
}

this has both triangles inside the tri buffer, and is generally more efficient than copying from multiple buffers, i'd personally recommend setting up things this way instead whenever possible.