Explanation:
It's a long answer. You have to find the area of the large triangle, the small triangle than subtract the two
A = 1/2(b)(h)
For the big triangle
A = 1/2(16)(4) = 1/2(64) = 32
For the small triangle
A = 1/2(8)(2)
We use 8 and 2 because that's half of 16 and 4, since at the bottom it says A and B are midpoints
A = 1/2(8)(2) = 1/2(16) = 8
Now we subtract
32-8 = 24 units