Determin the distance b/w a(4,3)and(8,12)b(2,1)and(2,-9)c(-1,-5)ana(2,-3)

I will do the last one, then you can show me how you did the first two .

c)
distance = √[ (2 - (-1))^2 + (-3 - (-5))^2 ]
= √[ 3^2 + 2^2 ]
= √13