Which expression represents the area of the shaded triangle?

[(1.9+2.4)x5.7/2]-[(2.4x5.7)/2]

Step-by-step explanation:

You take the area of the large triangle (which has a base of (1.9+2.4) and height of 5.7) and subtract the area of the small right triangle (whose base is 2.4 and height is 5.7)

Alternatively, you could use Heron's formula, but I doubt that's what they're looking for.