A field is 100m wide and 120m long both lengths have been rounded to the nearest metre

Question

a)Find the perimeter and the area of the field if these measurements are accurate. {Done}

b) Find the largest and smallest possible perimeter

c) Find the largest and smallest possible area

Answer 1

a) The answers you should have are perimeter=2(100+120)=440m. Area=12000sq m.

b) 100m rounded to the nearest metre could be between 99.5m to 100.5m and 120m between 119.5m and 120.5m. The largest perimeter would be 2(100.5+120.5)=442m (strictly < 442m) smallest is 2(99.5+119.5)=438m.

c) The largest area is 100.5*120.5=12110 sq m approx (<12110.25 sq m); the smallest=11890.25 sq m.