Tangrams are a very useful tool when teaching students about geometric shapes in an entertaining way. This PowerPoint uses the shapes of the 7 different pieces to teach about geometric concepts such as similarity, congruency, and area. If your school has an Ellison die cut for tangrams, you can give each child a set to use throughout this lesson. Your school may also have a complete class set to use. The puzzle had been popular in China before it was brought to the United States in 1815. You just need to click through each step of the lesson.