Question

An equilateral triangle has side of length 16.1cm,correct to the nearest millimetre find the lower and upper bounds of the perimeter of the equilateral triangle

Answer 1

For side length s, s(max) =16.149* cm and s(min) = 16.05 cm, where * denotes a repeating digit 
In an equilateral triangle, perimeter p = 3s. Hence p(max) = 48.449* cm and p(min) = 48.15 cm 
To the nearest millimeter, p(max) rounds to 48.4 cm and p(min) is 48.2 cm