Area of the triangle defined by the coordinates (-3, -4), (-7, 0), and (-3, 4).

Here: (Aₓ, Ay) = (-3,-4), (Bₓ, By) = (-7,0), (Cₓ, Cy) = (-3, 4)
Now, Formula of area of triangle is:

area = [Aₓ(By - Cy) + Bₓ(Cy - Ay) + Cₓ(Ay - By)] / 2

Substitute the values in to the expression, 
area = [-3(0-4) - 7(-4-(-4)) - 3(-4-0)] / 2
area = [-3(-4) -7(0) -3(-4)] / 2
area = [12-0+12] / 2
area = 24 / 2
area = 12

Final answer would be 12 units.

Hope this helps!