Photos/Videos of Interactive Mathematics Miscellany and Puzzles

    
Drag the corners of the box above to crop your new profile photo.
Saving your new profile picture

A beautiful problem by Professor Dorin Marghidanu .
P.S. 2
I will ask again to my followers to not copy our proof and post it here .
They embarasse theirselves (and myself too) with this kind of
atitude .
I will take some radical actions otherwise .