One of the cooler geometry activities I've ever seen

Google Maps + Paris + teaching instructions = seriously cool. Click on the purple pin to get started.

http://maps.google.co.uk/maps/ms?ie=UTF8&hl=en&msa=0&msid=106744469957319968675.000477900903fa3443371&source=embed&ll=48.813872,2.37751&spn=0.10671,0.298691&z=12