A 25 slide PowerPoint showing an incredible amount of things you can do with a 7 piece tangram. It covers 2D shapes, angles, area, proportion, percentages, fractions, square-roots, symmetry, compass directions, algebra, bearings and vectors. There is at least a weeks material for a KS3 or KS4 class and also could be used as revision. Please review it if you download it and put it to good use. The ideas used are adaptable and could be used for other square based patterns. It has interesting animations and some of the ideas are easier to access through animation.