First you have to find the angle B (check attachment)

Then you can find the last angle inside the triangle, which I'll call C

Now you can find angle A

 
        
             
        
        
        
Answer:
Step-by-step explanation:
There are 6 ways we can roll doubles out of a possible 36 rolls (6 x 6), for a probability of 6/36, or 1/6, on any roll of two fair dice. So you have a 16.7% probability of rolling doubles with 2 fair six-sided dice.
 
        
                    
             
        
        
        
Answer:
(a) Verified
(b) They are simultaneous equations
Step-by-step explanation:
Given


Required
Verify that:  is a solution
 is a solution
We have:

Substitute:  
 

Evaluate all products

Subtract:

<em>Because both sides of the equation are equal, then the point is a solution</em>
<em></em>
Also: 
Substitute:  
 

Evaluate all products

Subtract:

<em>Because both sides of the equation are equal, then the point is a solution</em>
<em></em>
<em></em>
Because the given point is a solution to both equations, then they are simultaneous equation