Asquare on a large calendar has an area of 4,220 square millimeters. between which two integers is the length of one side of the square?

its
between 64 and 65 millimeters

A square has four sides of equal length.
The equation for the area of a square is A = a²  where: A is the area and a is the length of one side.

Since the Area of the square is provided and the length is not, we need to get the square root of the area to get the of the length of one side of the square.

A = a²
4220 = a²
√4220 = √a²
a = 64.9615271

64.9615271 is between 64 and 65.

The scale factor of what ?