You already have at least one point, but you still need to find the slope.
To find the slope (m), use the formula: m = y2 - y1/x2 - x1
Select which point is your (x2, y2) and which is your (x1, y1)
NOTE: It doesn't matter which one you pick as long as you don't "mix-and-match" your x and y-coordinates
For example: you can't choose (-6,0) for a point.
I've chosen:
(x2, y2) = (2, 0)
(x1, y1) = (-6, 4)
Plug in the info into m = y2 - y1/x2 - x1:
m = 0 - 4/2 -(-6) = -4/2 + 6 = -4/8
Simplify: -4/8 = -1/2
m = -1/2
Now plug in the slope and ONE of the points into point-slope form
Tip: It doesn't matter which point you choose but I'd recommend choosing the point with all positive numbers, if you can, to prevent the confusion of double negatives:
b x h is finding a square or rectangle, but since a triangle is half of a rectangle or square you can divide that by 2. So, 8 (b) x 4 (h) = 32, 32 / 2 = 16. Hope this helps! :D