January 2018[change source]
Welcome to Wikipedia. Everyone is welcome to make helpful changes to Wikipedia. However, some of your changes, like those to "Obtuse angle", did not seem to be helpful and have been reverted or removed. If you want to try out changing Wikipedia to learn more about how it works, please use the sandbox. Thank you. DaneGeld (talk) 21:58, 8 January 2018 (UTC)
This is the discussion page for a person who has not created an account yet, or who does not use it.We have to use the numerical IP address to identify him/her. An IP address can be shared by many people. If you feel that things said here are not about you, you can create an account or log in to stop it happening again.