Why does my dad yell at me so much?

He's been yelling at me all morning. first, because he didn't like the way i shut the laptop. then, he called me lazy while i was putting dishes in the dishwasher. then, i put some soap on a plate that had grease on it and he screamed at me until i cried, then he gotupset because i was crying. He started to take apart what i had done with the dishwasher, pointing out every little thing that didn't go along with the way he did dishes. its like that every time he makes me and my sister wash dishes. i asked him why he didn't just do it if he knew we couldn't do it right. he yelled some kind of wierd excuse about how he's teaching me how to do it right, using methods he's yelled at me for using before... why is he yelling at me so much? i don't know why, but if he gets mad, he'll literally look around for something else to yell about. why?