User contributions
- 14:27, 2 September 2021 (diff | hist) . . (+544) . . Talk:2509: Useful Geometry Formulas
- 14:20, 2 September 2021 (diff | hist) . . (+472) . . Talk:2509: Useful Geometry Formulas
- 02:25, 2 September 2021 (diff | hist) . . (+266) . . Talk:2509: Useful Geometry Formulas (How to explain the angle theta)