There are some very clever tips at the Daily Post today http://dailypost.wordpress.com/2012/11/02/weekly-photo-challenge-geometry/

Now, I’m sure the geometry was accurate in these three very old cathedrals but sadly craning my neck and holding a camera still and straight has made them look a touch wonky! Here is Gloucester cathedral.

Chichester

and last, the best of all is Exeter

check out the fan vaulting in my earlier post if you don’t believe me! https://lucidgypsy.wordpress.com/2012/04/28/exeter-cathedral-2/

As I looked up, Lynne looked down!http://lynneayersbeyondthebrush.wordpress.com/2012/11/02/dont-forget-to-look-down/#

And here is a newbie with a lovely quilt!

http://2far2shout.wordpress.com/2012/11/02/weekly-photo-challenge-geometry/