Puzzles
Unit octagon
![](javascript:showlimage("octagon.png"))
The diagram shows a regular octagon with sides of length 1. The octagon is divided into regions by four diagonals. What is the difference between the area of the hatched region and the area of the region shaded grey?
![](javascript:showlimage("octagon-a1.png"))
![](javascript:showlimage("dodecagon.png"))
If you enjoyed this puzzle, check out Sunday Afternoon Maths XII,
puzzles about area, or a random puzzle.
puzzles about area, or a random puzzle.