Part B for regular can openers.
Part A for left-handed ones.
Update: VIDEO instructions: YouTube - How to open a tin of spaghetti
They say "You can find anything in the Internet", and I believed them... until today. Sure you can find a lot and lot of things, especially for free on the Internet. But I could hardly find any information on how to use a can opener. Actually I couldn't find any, except a small picture, which too was wrongly oriented! Here goes the story...
First I bought a can of lychee (it is a fruit). Now I found a can opener in my house. Wow I've never seen it before in my life, and I don't know how to use it. Well, I like to experiment with things, so I put the can opener on the can in different positions, trying to get it work. There was one part of the can opener which looked sharp, and so was thought to be the part which actually cuts the metal. (Sadly later I found that this part doesn't even touch the can during operation.)
Then I began my faithful search on Google. Typed in "how to use can opener" and clicked Google Search (I wasn't feeling lucky on Google... heck I never feel lucky on Google!). My expectation of 100s and 1000s of pages with illustrated directions on how to use the thing was shattered when I found that the number of pages with such information is equal to... zero! Rather to my surprise, the first result says that can opener is actually a bad design! There were other pages which says about the history of can openers, can opener cartoons (what the heck?), P-38 can openers (something that is not even close to the one I have!)... etc etc etc... but no instructions...
After a bit of keyword tweaking and other trials, I reached the Wikipedia page on can openers. I found other pages and went about doing other stuff for a while. Then giving up hope, I decided to cut the metal using a screwdriver I found. So I used it to cut the metal a bit, and then used a pair of pliers to tear it open. Later when all are over, I came back to the Wikipedia page again. Over there I found this statement: A can opener (also known as a tin opener) is a device used to open metal cans. (Why didn't I find it earlier?)
Hmm... that gives me a little hope. It is also called a tin opener.
So I searched "how to use tin opener" in Google, and viola... Err, I still did not find any satisfactory results... hold on... this seems interesting... "Tin opener with geared rotary action (Red) left handed"
I went to that result, and I found, though not exactly, what I had been searching for. The web page was actually designed to sell left-handed can-openers, but luckily it also had illustrations on how to use them.
Update: VIDEO instructions: YouTube - How to open a tin of spaghetti (embed below). By the way, that's not me. Thanks to Kumarika for nudging me to find the video.
The webpage had only Part A and Part C of the picture above. They were advertising left-handed can opener as more convenient than regular ones, and A illustrates left-handed one, while C illustrates right-handed regular one. Showing C, they say how inconvenient it is to use it. Actually, they're wrong. I flipped A to get B, and viola! The REAL way to use a right-handed can opener emerged. Hold with left hand, turn with right hand. And I tried it out, and found B was easy and more natural than C.
I really wonder if people would ever use regular can openers as depicted in C. My best guess is, majority of right-handed can openers in the world are used as shown in B. These people just created C to give a wrong idea to a visitor. If the visitor doesn't know how to use a can opener, he would assume that C is how a regular one is used, and therefore A would seem natural and easier to him. If the visitor already knows to use it as shown in B, he would wrongy assume that his way of using is not the standard way, and that the standard way is much harder, thus making him think of buying a left-handed can opener. Blah blah blah what they make people believe in order to market!
Ok here is a picture of the can and it's cut out top and bottom. The top was first torn open with screwdriver and plier, and later cut out with the can opener. The bottom was neatly cut out with the opener.