What shapes can I use for my picture password?
Your picture password consists of a picture you've chosen and three gestures that you draw directly on the screen. The three gestures can be any combination of circles, straight lines, and taps. The size, position, and direction of your gestures, and the order in which you draw them, become part of the picture password. To sign in, you'll need to repeat the same three gestures on your picture in the same sequence.
When you're drawing your gestures for the first time, they're outlined on the screen to help you remember them. Windows interprets a wavy or curved line as a straight line, so even if you try to draw a wavy line, the outline will appear straight. So, it's a good idea to stick with straight lines, circles, and taps.