The distance between (0,3) and (3,0) = sqrt 18
The other 3 distances on the rhombus must also be = sqrt18.
Distance between (3,6) and (6,3) = sqrt 18 , also distance between (3,6 and (0,3) = sqrt18 and distance between (3,0) and (6,3) = sqrt 18
Answer is (3, 6) and (6 , 3)