The leg between the given vertices is 6-1=5 units long. The other leg is
.. A = (1/2)bh . . . . . formula for area of a triangle
.. 10 = (1/2)b*5 . . . . substitute the given information
.. 4 = b . . . . . . . . . . .the other leg is 4 units long.
The third vertex can be any of (-4, 1), (-4, 6), (4, 1), (4, 6).
We presume one of these is on your list of answer coices.