Since the angle  
100
°  is in the second quadrant, the reference angle formula is  A
r
=
180
°
−
A
c.   A
r
=
180
°
−
100
°
The reference angle is  A
r
=
80
°
.
80
°
 
        
             
        
        
        
Lol I'm glad to answer your questions :D
So in the last question, it uses the word "per" which basically means you would have to multiply the number of pounds times 1.69
So it would be $1.69a
        
             
        
        
        
Answer:
A is the answer i believe 
Step-by-step explanation: