Perimeter [ GM3.1 Support Plenary] i) Imagine having 12, 1 cm2 tiles. How can they be arranged to give a shape with the smallest perimeter? (You may find some squared paper useful.) ii) What about 16 or 18 tiles? Which sort of shapes seem to give the smallest perimeters? Experiment with different numbers of tiles. b) Repeat the above but for triangular tiles. You will need some triangular dotty or isometric paper. Preamble These activities are suitable for small group work concluding with whole-group discussion. Possible content Looking at the patterns and finding perimeters. Resources Triangle or isometric paper. Solution/Notes a) i) Smallest perimeter is 14 cm ii) 16 squares is 12 cm (4 by 4 square), 18 squares is 18 cm (4 by 4 square with 2 squares added to the side.) In simple terms the closer the arrangements get to a square the smaller the perimeter. b) The shapes which are closest to hexagons have the smallest perimeter. Original Material © Cambridge University Press 2010 Original Material © Cambridge University Press 2010