Sorry, he gave you a false answer :/
Answer:
(3,4) and (6,2) could be vertices of a right triangle with (6,4) and (3,2)
(0,0) is on the same line as (6,4) and (3,2) so it doesn't even form a triangle, much less a right triangle.
(3,6) forms a scalene isosceles triangle, but not a right triangle It's a 4-sqr13-sqr13 triangle
(4.5,3) also forms an abtuse isosceles triangle, but not a right triangle It's a sqr13 - sqr3.25 - sqr3.25 triangle
Explanation: