A rectangular game board measures 126 centimeters by 90 centimeters. The game board is divided into small squares of equal sides. a) Find the longest possible length of the side of one of the squares.

18cm^2

Step-by-step explanation:

First, work out all the common factors, then take the highest.

90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90

126: 1, 2, 3, 6, 7, 9, 18 ( + (there's no more that are the same as that of 90))

So, the highest common factor is 18, therefore, 18 is the longest side you can have