To solve for the values in the variable knowing that the sum of all angles in a triangle add to 180 degrees. Simply use this fact to determine the value of z. 
Z = 180 - 115 = 165
Then to solve for x, do the same thing. Add up 51 and 45 and subtract the sum by the 165 degrees. 
To solve for y, simply knowing the angle that is present for both 70 and the unknown is 180. Subtract 180 from y. 
To actually solve for y add up the value for x and 51 and subtract that amount by 180 degrees.
        
             
        
        
        
Answer: A 
Hope this helps!
        
             
        
        
        
<span>Premise
1: If a polygon was translated to the right, then its image is
congruent to its pre-image. 
In symbols: p => q
Premise 2: If an image is congruent to its
pre-image, then a rigid transformation was performed. 
In symbols: q => r
By the law of silogism 
(p => q) and (q => r) => q => r
So, the conclusion is that </span><span>if a polygon was translated to the right, then a rigid transformation was performed. <---- answer</span>
        
                    
             
        
        
        
Step-by-step explanation:

 
        
             
        
        
        
The complete question is: Henry knows that the circumference of a circle is 
18π inches. What is the area of the circle?
Solution:Circumference (C) of the circle can be written as:

Using this value of radius, we can find the Area(A) of the circle.
Therefore, area of the circle having a circumference of 18π inches will be 81π inches²