a = a1
a drawing really does here:
so i draw the horizontal line y=2 and the vertical line x=-2 at this intersection i put b (this is where my right angle is going to be). so point b is at (-2,2). point a is 5 units long and is also on y=2 so this point has to be (3,2) or (-7,2) -doesn't matter i will go with (3,2).
now we know c is at (-2,y) we don't know the y yet bet we know that c is on x=-2.
we have the area of the triangle is .5bh=12.5
we know the base length is 5 (ab)
we have the height is (2-y) if you look at your
solve for y to get the y-coordinate for c
divide both sides by 2.5 giving:
now subtract 2 on both sides