View full screen in your browser. This ITP allows you to place shapes around a point and investigate their angles. You can opt to display the shapes in one, two or four quadrants. The first shape is placed on the screen in the first quadrant with one of its sides horizontal. Additional shapes are rotated around the central point to fit against the previous shape. In some shapes side lengths and angles are generated randomly. Shapes generated can be dragged to new positions and overlaid to form new intersecting shapes and angles.
View full screen in your browser. This ITP allows you colour the equilateral triangles set out on an isometric grid. The grid can be hidden or become an isometric pin board. An ‘elastic band’ can be stretched around the pins to create outlines. One of three different rhombuses can be selected and dragged to different positions on the grid. These three rhombuses can be locked together to form the isometric view of a cube. Skeleton outlines of rows and columns of cubes can be formed this way and by colouring in two adjacent triangles, coloured faces can be created. The ITP can be used to explore properties of shapes and space. The making of different shapes and patterns can support the teaching of number and problem solving, for example, to explore the interior and exterior angle and symmetry of polygons made up of equilateral triangles and to identify the patterns in triangle numbers. The flexibility offered by the ITP allows it to be used to support a variety of teaching and learning contexts in mathematics. It can be used in conjunction with the Area ITP to look at the nets of 3-D shapes represented on the isometric grid.
View full screen in your browser. This ITP displays regular polygons with 3 to 10 sides. A background grid can be revealed and hidden and the displayed polygon can be enlarged using the pointers on the polygon button. The polygon can be translated and rotated. A vertex on the polygon can be dragged to another position to change its shape and properties. Double clicking on a vertex allows you to add remove the vertex or to add an extra vertex at the mid point of an adjacent side. You can use the ruler or protractor to measure dragging it and using the circular button to rotate it to the required position. The ITP can be used to explore the properties of regular and irregular polygons. Children’s understanding of the angular properties of polygons can be developed. Children’s hypotheses about properties of sides and internal and external angles can be verified by measurement. Using the grid, children can explore the areas of polygons; identify which polygon’s vertices fit onto the grid points and look at how they calculate the areas of rectilinear shapes.