where are vertices A located?

Answer:
(3, 4) works, but there are other correct answers.
Step-by-step explanation:
We are given 2 vertices of a right triangle.
There is an infinite number of points that can be the third vertex and form a right triangle. There is not enough information to answer with a unique point.
One answer is point (3, 4) making <A the right angle of the triangle.