Flying origami crane.

Step 5 Mind bending.

Now that your minds are warmed up from those geometry exercises, prepare to flex them. You will now open one of the triangular flaps, and push down on the top ridge, causing it to deform into a square (geometric transformations can be exciting, eh?)

If you've gotten this so far, repeat for the opposite side. Or adjacent. Whichever you want to call it.