adzel
draw the paralleogram and consequently u will get the third side
A=(1,1) B=(4,6) C=(8,6) then u will get that D=(5,1)
use the rule =
square root of any 2 points let's take (4,6) and (1,1)
square root of (4-1)^2+(6-1)^2
square root of (3)^2+(5)^2
square root of 9+25
square root of 34
Answer=5.83
(Tht's the third question)