A math-magic article I wrote for the German magazine Zeit Wissen: with the 13 triangular and square pieces (fig. 1) it is possible to form two large squares shown in fig. 2. Though the second large square has an extra piece the dimensions of the squares seem to be the same! Can you explain why this is possible?

# Tangram

## TangraMagic Puzzle

*TangraMagic*, a new manipulative puzzle for classrooms or just for fun..

*TangraMagic*

This unique puzzle of my creation is ideal for teaching math basic skills, problem solving and critical thinking in an exciting way! The vanishing geometrical effects will hold juniors and seniors’ attention. All the secret of this game is concealed in two numbers: 5 and square root of 7.