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.
sqrt(2.2² + 2.8² - 2(2.2)(2.8) cos 80°
sqrt(2.2² + 2.8² - 2(2.2)(2.8) cos 80°
Natural Language
Math Input
Extended Keyboard
