## Thursday, September 30, 2010

### The Tangram Puzzle Set

The tangram puzzle set is composed of seven pieces.  One of the piece is a square, another piece is a rhomboid, and the other five pieces are isosceles right triangles of various sizes.  Of these triangular pieces, two are small size triangles, one is a medium sized triangle and and two are large size  triangle.  The area of a large size triangle is twice the area of the medium size triangle.  The area of the medium size triangle is twice the area of an small size triangle. The area of the square is also twice the area of an small size triangle.  The area of the rhomboid is the same as that of the square.

Arranged correctly, the shapes can be fitted together as a large square, rectangle, or triangle. They can also be arranged in a variety of complex shapes, including fanciful ones (like the rabbit illustrated here).There are many ways to play with tangrams. The simplest way is to let kids create their own complex shapes. But traditionally, tangrams are treated as puzzles. The player is shown a target shape (in outline, or silhouette only) and then asked to recreate that shape using the seven pieces.
As noted below, tangrams can also be used to teach kids to measure area without formulas—an approach that should help kids develop an intuitive sense of geometry.