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1.5 Measurement. AS 91030. Perimeters of Polygons. Learning objectives. I can find the length of missing sides I can find the perimeter of polygons. Perimeters of Polygons. Keywords. A polygon is a shape with straight edges The perimeter is all the way round the outside.
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1.5Measurement AS 91030
Perimeters of Polygons Learning objectives • I can find the length of missing sides • I can find the perimeter of polygons
Perimeters of Polygons Keywords A polygon is a shape with straight edges The perimeter is all the way round the outside
Perimeters of Polygons 5 cm 6 cm Perimeter = 17 + 17 = 34 cm Perimeter = 6 + 4 + 6 + 4 = 10 cm 4 cm 12 cm 6 cm Perimeter = 6 + 5+ 10 + 5 =26 cm 15 cm Perimeter = 15+15+15+15+15 =75 cm 5 cm 5 cm 10 cm
3 cm Plan A Find the missing sides and add everything up (click and they appear) 7 cm 5 cm Perimeter = 12 + 8 + 3 + 7 + 5 + 5 = 40 cm 12 cm 5 cm 8 cm Plan B Click for cool animation to see the problem a different way 12 cm So now we have a rectangle and the perimeter = 12 + 8 + 12 + 8 = 40 cm 8 cm
Find the total length of black lines. 90 cm side edge 2 x 120 cm lines = 240 cm top edge 2 x 90 cm lines = 180 cm inside there are 2 more 120 cm lines (click to see) and 2 more 90 cm lines which I didn’t animate 120 cm Total length of black lines = 4 x 120 + 4 x 90 = 840 cm
Success Criteria • I can find the length of missing sides • I can find the perimeter of polygons