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 
The radius is half the diameter of the circle. If the radius gets larger then the whole circle grows. When the circle gets larger, the area gets larger too.
The arithmetic sequence of 161,147,133,119
Compute the general progression formula of 161,147,133,119 d=-14, a↓n+175
Compute ᵃ₂₂ = -133
-10 is the answer
Plug in -4 for n so 2x-4-2=-10