The surface are of the shape is 251.5 units (sorry if that is wrong)
        
                    
             
        
        
        
Answer: 60°
Step-by-step explanation: A straight angle is 180°
180°- 120° = 60°
 
        
             
        
        
        
Let's begin by listing out the information given to us:
There are four students: n = 4
Number of students to be selected: r = 2
To calculate the combination of 2 students to be chosen, we use:

Therefore, there 12 possible combinations from these 
 
        
             
        
        
        
A's area is 4x3=12, B=2x3=6, so yes, A is twice the area of B
a Answer: YES
b Answer:  One side doubled, the other stayed the same, so area doubled.