Videos Test Yourself Books MathFacts Math Diagnostics Math Tricks Daily PhysEd
Class Photos Worksheets Math Genius Musiclopedia Techlopedia Teacher Timesavers Study Guides
The Prioress

Answer :

The Abbot of Chertsey was quite correct. 
The curiously-shaped cross may be cut into four pieces that will fit together and form a perfect square. 

How this is done is shown in the illustration.

Medieval Brain Teasers