I got this idea off my favourite opitcal illusions blog, Mighty Illusions! Not my idea, but I made the triangle all by myself I think I'll make another one and improve it a bit, try to guess how I did it. O, and no photoshop...
yuppers, the hardest part was getting the notch at the top left corner perfect, next time I'll cut the part right above where they 'connect' so the lighting is the same at the top. thanks