How many ways to spell a rectangle with a jigsaw puzzle

There are 18 ways to spell a rectangle with a jigsaw puzzle. There are 3 ways to spell it with 3 pieces, 4 ways to spell it with 4 pieces, 6 ways to spell it with 5 pieces, 3 ways to spell it with 6 pieces, and 2 ways to spell it with 7 pieces.

How to put together a rectangle with a jigsaw puzzle:

First step: put two large triangles diagonal to diagonal to form a square on the left side, and use one of the right-angled edges of the large triangles as the width of the rectangle that you are going to put together.

Step 2: Place a small triangle on top of the right side of the square from step 1, so that its two right angles are facing up and to the left, and then use the long side of that parallelogram next to the hypotenuse of the small triangle, with a short side connecting to the right angle side of the small triangle that is facing up.

Step 3: Use the right angle side of the center triangle against the other long side of the parallelogram, noting that the hypotenuse of this center triangle faces right and becomes the right width of the rectangle.

Step 4: With one square and small triangle left, the square is placed in the left empty space and the small triangle is placed last.

The tangram is a kind of intellectual game, so the name suggests, tangram is composed of seven boards. The seven pieces of the board can be assembled into many shapes, such as: triangles, parallelograms, irregular polygons, players can also put it into a variety of characters, images, animals, bridges, houses, towers, etc., can also be some of the Chinese and English letters.

The tangram is a traditional Chinese intellectual game, and the tangram has a variety of intellectual development functions. In the puzzle, need to hand-eye cooperation, because the hand-brain connection, the fine activities of the hand not only train the children's hand stability, but also stimulate the development of brain cells.

The simple structure of the tangram board is easy to make people think that it is easy to solve its problems, in fact, this idea is one-sided. There are more than 1,600 patterns that can be made with a jigsaw puzzle, some of which are easy to put together, some of which are quite cryptic, and some of which are plausible and full of contradictions.