How did you get 41 and 43

Refer to interactive solution 17.45 to review a method by which this problem can be solved. the fundamental frequencies of two air columns are the same. column a is open at both ends, while column b is open at only one end. the length of column a is 0.504 m. what is the length of column b?

Need on this geometry question. explain how you did it.

Vertical angles must check all that apply