Puzzles
Equal side and angle
Source: Jim Noble on Twitter
![](javascript:showlimage("equal-side-and-angle.png"))
In the diagram shown, the lengths \(AD = CD\) and the angles \(ABD=CBD\).
Prove that the lengths \(AB=BC\).
If you enjoyed this puzzle, check out Sunday Afternoon Maths XXXVIII,
puzzles about trigonometry, or a random puzzle.
puzzles about trigonometry, or a random puzzle.