Answer:
x  = 6
Step-by-step explanation:
First find the gradient,

Since this line has no gradient, it means that it's a horizontal or vertical line. We cannot substitute in the values because the gradient is 0 so this line will only be x = 6
 
        
                    
             
        
        
        
-4.3,-6/2,-2.5,5/4,4,5.33,8.2
        
             
        
        
        
Are you saying the side is 6 inches? ie lenght of the base. i just dont think u have enough data there to work this out?