Since your interested in square root each value in each radicand you can compare them directly. A value of 6 is greater than 3, which is greater than 2 . The √6 and the √3 terms are each multiplied by 2, which will not alter which is greater than the other . And since √2 is not multiplied by 2, it remains the smallest
So , the correct order is
2√6 cm > 2√3 cm > √2 cm.
