Answer:
Studying every single instance of a thing is impractical or too expensive
Step-by-step explanation:
With sampling we a have a lot of data without much effort.
 
        
             
        
        
        
The sum of a trapezoid is 360 degrees
45+90+90+x=360
45+180+x=360
225+x=360
x=135
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
Take 20( cosine of 75 degrees)
the answer is 5 ft
 
        
                    
             
        
        
        
Basically divide each fraction to get the simplified version of each answer. You divide each fraction by the highest multiple. 
4/16 can be divided by 4 to get 1/4
12/18 can be divided by 6 to get 2/3
4/10 can be divided by 2 to get 2/5
16/20 can be divided by 4 to get 4/5
        
             
        
        
        
The answer is (-18, -2). Just multiply by 2!