Hi all, I was wandering on the web to collect some solid and justifiable reasons to answer a question "Why we always choose a unit circle."? I saw several websites and meanwhile I saw this post https://www.physicsforums.com/threads/trig-unit-circle-why.475575/. I saved it. But overall, I couldn't get some good set of reasons, I then collected some reasons, prepared an article and came here today but couldn't see an option to submit my own reply, don't know why it's happening with my account. However I want to share that article here. Any advice on should I copy paste it here or what? It's live on a blog. Please reply. Thank you.