## Measurement precision

How precisely must we measure the sides of a rectangle with approximate dimensions $$6\times 8\, cm$$, in order to

• #### Variant 1

determine the perimeter of the rectangle with a precision of 1 $$mm$$?

• #### Variant 2

determine the area of the rectangle with a precision of 1 $$mm^2$$?

• #### Variant 3

determine the length of the rectangle's diagonals with a precision of 1 mm?
(Ignore the fact that we could measure the diaonals directly.)

• #### Variant 4

determine the area of the rectangle with a precision of 1 $$cm^2$$?