They are vertical angles, thus they are equal to each other:
5x + 12 = 6x - 10
22 = x
x = 22
        
                    
             
        
        
        
Answer:
√85
Step-by-step explanation:
The given shape is a right angled triangle.
Let the missing side length be " x ".
By Pythagoras theorem,
x² = 6² + 7²
x² = 36 + 49
x² = 85
x = √85
Therefore, the missing side length be √85.
 
        
             
        
        
        
Answer:
0.40
Step-by-step explanation:
Sin(T) is Opposite over Hypotenuse, which is RS/ST. 
ST = sqrt(43) so we can plug that in.
To find RS, use the Pythagorean theorem, so, 6^2+ (RS)^2= 43.
36 + (RS)^2 = 43
RS^2 = 7
RS = sqrt(7)
Thus, Sin(T) = sqrt(7/43) or 0.40
 
        
             
        
        
        
Where’s the shape, you didn’t add anything