Opening a locked door with a key is a common task that most people will encounter at some point in their lives. While it may seem like a simple process, there are actually a few things you need to know in order to do it correctly.
The first thing you need to do is find the correct key. The key should be the same size and shape as the lock. If you are not sure which key to use, you can try each one until you find the one that fits.