<span>FG = EG−EF
= 10 − 4
= 6</span>
        
                    
             
        
        
        
Can you post this and provide a picture please so I can help you ? 
Explanation:
        
             
        
        
        
Answer:
45
Step-by-step explanation:
9x10/2=45
 
        
             
        
        
        
Answer:
∠a = 10°
Step-by-step explanation:
The measure of ∠a = x
The measure of ∠b = 4x-30
It is also mentioned that the measure a and measure b are vertical angles. We need to find the value of a.
For vertically opposite angles,
∠a = ∠b 
x = 4x-30
or
4x-30=x
Taking like terms together,
4x-x= 30
3x = 30
x = 10
So, the meausre of ∠a is equal to 10°.
 
        
             
        
        
        
Are you learning how to arc things