if question will be
squre roots( (x2-x1)^2 +(y2-y1)^2)
if x1=0
x2=0
y1=12
y2=20
then putting the value of x1,x2,y1,&y2
squre root ( (0-0)^2+(20-12)^2)
squre root (0 +64)
squre root of 64 is 8
then 8 is the answer of this question

May 23rd, 2015

if i is not as shown above, please don't give me bad reputation, the question is not clear