What is this all about?
If you want to reveal the true to you friends and family, you are going to have to make them use reason. They will eventually have to use their own minds and their own reasoning. You will never be able to force this true on them. Asking someone to accept the Flat Earth as their new, true reality is a life shattering request. You are basically asking them to throw out everything they have ever believed (and everything that is build upon those beliefs), and replace them with new beliefs. Not an easy thing to do for anyone. Especially if they submerged as deeply in the matrix of false realities as the average Westerner.
You are going to have to LEAD your friends to the true. You are going to have to show them one piece of the puzzle at a time. You should ask them questions, and let them answer the questions on their own. They are going to have to question their own reality. Only then will they slowly accept the truth that they see all around them.
This is a list of the some of the most commonly used, and easy to understand arguments for the Flat Earth.
I have tried to place them in order of use, from the first to the latter. The top few topics you can introduce with or without supporting pictures and videos. Or you can open the picture first, let the victum look at it and figure out what he/she is looking at and then ask them the related question. This method will force them to rationalize their beliefs to the new evidence you present. Anyway, give it a try and let me know how it goes.