You can use the midpoint formulae as I have in the picture below
 
        
        
        
Answer:
The given sides does not form a triangle 
Step-by-step explanation:
The given sides does not form a triangle 
We know the triangle property which states that the sum of any two sides of the triangle should be greater than the third side.
Here given th esides of the triangle are 6x,7x,21x
6x+7x=13x < 21x
for any value of x the above equation does not satisfy.
 
        
             
        
        
        
Answer:
Die= 6 possible outcomes
spinner= 4 possible outcomes
word= 4 possible outcomes
alphabet= 26 possible outcomes
cards= 15 possible outcomes