Question 990979
Case-1
let (5,8) be endpoint and (9,14) be midpoint
Let other end point be (x,y)
So, {{{(x+5)/2 = 9}}} and {{{(y+8)/2=14}}}
=> x = 13 and y = 20

Case-2
let (5,8) be midpoint and (9,14) be endpoint
Let other end point be (x,y)
So, {{{(x+9)/2 = 5}}} and {{{(y+14)/2=8}}}
=> x = 1 and y = 2

So possible coordinates of other end points,
(13,20) and (1,2)