Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
quadrilateral( (2, 4), (2, -2), (-1, -2), (-2, 4))
quadrilateral( (2, 4), (2, -2), (-1, -2), (-2, 4))
Natural Language
Math Input
Extended Keyboard
