image automatic resize

i was wondering if i can make all the images in posts resize to a specific size, because when they are like 1200x1024 it really messes up the whole page. so please can u tell me where can i change the options for that if possible

General>messages and Emails>Configuration
Images resize :

Thanks! I don't know why I didnt see that, I've checked that before I know I scrollled through every tab in the CP lol, but I guess it didnt just catch my eyes Thank you!