Besides jigsaw puzzles, there are different types of solution brain teasers, which require the structuring of a shape or the creation of a sequence . Brain teasers have existed for thousands of years , among the most famous are: the Tangram, the Hanoi Tower and Rubik’s cube.
The Tangram The Tangram puzzle became popular during the 19th century in China and 20 years later spread to Europe and the United States. The name means “The seven stones of wisdom”, and it is made up of seven tablets called tan, which are made of the same material and usually of the same color, but with different shapes one from the other, 5 triangles of different size, 1 square and 1 a parallelogram. At the start of the game, the tans are placed so as to form a square, and then the scope of the game is to try and form complete figures by using all the pieces, but without any overlappings.
The Hanoi Tower A brain teaser invented in 1883 by the mathematician Edouard Lucas. The Hanoi Tower consists of three towers and a certain number of rings of decreasing size, which can be inserted into any of the towers. The game starts with all the rings stacked in decreasing order on one of towers, so as to form a cone. The game consists in placing all the rings onto the last tower, by moving one ring per time, you cannot place a larger ring over a smaller ring.
Rubik’s cube In today’s modern era, the invention of new materials, such as plastic, has led to the development of a great variety of brain teasers, among which, the cube  the most famous in the world  by Hungarian engineer Rubik, designed for educational purposes in 1974, that has now become the object of real puzzle solving championships. The classic Rubik cube has 9 squares on each side for a total of 54 squares, which differ in colour, one from the other, for a total of 6 different colors. The cube solution is obtained when each side has all the 9 squares with the same color.
