Question 979790
Two points are on the x-axis, one at (a,0), the other at (0,0)

The third point is at (-1,3).
The area is (1/2)bh; b=a and height 3, since the height is the perpendicular from the x-axis to y=3. The base has to be 4 in length, so that bh=12 and (1/2)bh=6.
(4,0) or (-4,0) both work.
One gives an acute triangle, the other an obtuse triangle, but the base is 4 and the height 3.