Skip to content

Challenge 390: Octagon Area

 This problem concerns a regular octagon with vertices labelled A, B, C, D, E, F, G and H (in order) , and centre O,

The edges AB and ED are extended to make straight lines which intersect at point X. 

The distance from O to X is 1 unit.

Find the area of the octagon ABCDEFGH.

Submit your solution

Please do send in your solution to this problem to  weeklymaths@kcl.ac.uk  You can scan or photograph your written work, or type your solutions. If this is your first weekly maths challenge solution, please include your year group and the name of the school you attend. We'll be happy to provide feedback on your solution, assuming that you are in year 11 or below. If you are older than this, we hope you enjoy trying the problems and reviewing your solutions against those we publish on the website.