I’m going to say B I could be wrong
The denominator would still be the same you placed the marble back into the bag
Answer: 
Step-by-step explanation:
Given
Two forces of 9 and 13 lbs acts
angle to each other
The resultant of the two forces is given by

Insert the values

Resultant makes an angle of

So, the resultant makes an angle of
with 9 lb force
Angle made with 13 lb force is 
Answer:
4
the fourth expression is a rational