Mr Ethan divide the a land that measures 42m by 60m into equal what should be the size of largest square ​

The size of the largest square is 36m². To find for the measures of the squares, use the common factors of 42 and 60. Among the common factors, choose the greatest.
Find the factors of 42 using the listing method.
42 - 1, 2, 3, 6, 7, 14, 21, 42
Find the factors of 60 using the listing method also.
60 - 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60
Identify the common factors of 42 and 60.
42 - 1, 2, 3, 6, 7, 14, 21, 42
60 - 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60
Common Factors: 1, 2, 3, 6
Therefore, the size of the largest square is 36m² since 6m x 6m is equals to 36m².