Entroper on 01 June 2007
| txags911 said: All of this is ASSUMING that the lines crossing in the middle are straight, and that the shared angles in the middle are equal. Not an assumption you can make based on the diagram. |
In geometry it is commonly accepted that you can assume that intersecting lines are straight, so that gives you the opposite angles. It is not commonly accepted to assume that lines or angles which look equal are equal, though.
