How much lawn feed
                   do I need?
                                        How much edging 
                                  do I need to go around              The gardener 
                                         the lawn?                    needs to work 
                                                                      out the 
                                                                      perimeter and 
                                                                      the area of 
                                                                      the lawn
      © Nuffield Foundation 2011
         The perimeter of a shape is the total length of its sides
                                                                                                                                                    length
                  Perimeter of a rectangle
                  =   length + width                                                                            width
                           + length + width                                                                                                                                                      width
                                                   5 m                                                                                                length
                                                 lawn                                         3 m              Perimeter of this lawn 
                                                                                                                                                         = 16
                                                                                                               = 5 + 3 + 5 + 3                                          m
                                                  Think about
                                                  Think about
                                                  Is there another way to find the 
                                                  Is there another way to find the 
            © Nuffield Foundation 2011            perimeter?
                                                  perimeter?
                                                Area
         Area measures the surface of something
                     1 metre
                                                       1 cm                      1 mm
                              2                                       1 mm 1 mm2
    1 metre              1 m              1 cm         1 cm2
                1 square metre
      © Nuffield Foundation 2011
                             Area of a rectangular lawn
                                                     5 metres long
                  3 metres wide
                           The area is 15 square metres                       2
                                                                     = 15 m  
                           Area of a rectangle  = length × width  
      © Nuffield Foundation 2011
                    Area of rectangle = length × width  
                         65 m
                                                       Area of field  = 65 × 32 
                          field               32 m
                                                                          = 2080m2 
                   21 cm
                                               Area of the page = 30 × 21 
                    page        30 cm
                                                                        = 630       2
                                                                                cm 
      © Nuffield Foundation 2011