# Measure and calculate the perimeter of composite rectilinear shapes in centimetres and metres

New Maths Curriculum (2014): Year 5 objectives.

 Perimeter of Shapes Find the perimeter of a variety of 2d shapes, or of compound shapes. ITP Area View full screen in your browser. This ITP allows you to colour in cells on a grid, a full cell or half a cell, or to place a circular counter into a cell. There are three choices of grid size: 5 by 5, 10 by 10 or 20 by 20. The grid can be hidden or replaced by a pin board around the points of which rubber bands can be stretched. The making of different shapes and patterns can support the teaching of number, shape and space and problem solving, for example, to identify the positions of counters in a given sequence or to find the number of nets of an open cube. The flexibility offered by the ITP allows it to be used to support a variety of teaching and learning contexts in mathematics. This resource is freely available to download from the archived Primary Framework site. ITP Polygon 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. This resource is freely available to download from the archived Primary Framework site. For more shape and space resources click here.