Answer:
8
Step-by-step explanation:
Take the biggest value and smallest value, and subtract the smallest value from the biggest value:
9-1=8
 
        
                    
             
        
        
        
Step-by-step explanation:
You need to know some geometry rules.
For example:
Angle sum of a triangle is equal to 180 degrees.
Straight line is equal to 180 degrees.
Other rules I have attached.
If you have any confusion over these I will be happy to answer your questions.
 
        
             
        
        
        
Answer:
(11/2, -1)
Step-by-step explanation: