Can you make a picture to illustrate the third proof of Thales' theorem on Wikipedia? The current picture is outdated and refers to an older version of that proof. Thales' theorem is about triangles in a circle... I don't see any auxiliary circle in that proof... Yes, please do! That picture is almost impossible to view, it has black lines on a very dark background. Also the rotated triangle appears to be missing. The triangle and the rotated triangle are supposed to look the same. Together they form a rectangle. You have no idea what you are drawing, do you? Please do! You made ABCB' be a square. This is confusing. B should be off to one side, not exactly at the top in the middle. This looks much better! Please remove the symbol for a right angle (or put it inside the actual right angle, it is slightly rotated now), and remove the symbol near the center which I think means rotation.