Answer:
a. 1
b. 3
c. 

Explanation:
To find a distance between two points or the length of the segment, we use the following formula: 

 a. A = (3,5) and B =(3,6) 
AB = 
 =
 = 
 
 
b. C = (-2,-3) and D =(-2,-6)
CD = 
 
 
c. E = (-3,1) and F =(-3,-1) 
EF = 
 
 
Hope it will find you well.