Explanation:
A you see here, we have 3 different shapes. a Triangle, a big and small rectangle. Lets start with the triangle.
between the 8 in's, theres a gap. 5+4=9,
9+8+8=25. we have the length of the triangle.
9*25 divided by 2= 112.5. thats are area of the triangle.
for the bigger rectangle, 20*9=180, the area of the rectangle, and the smaller rectangle at the bottom is 16.
Now we add:
112.5+180+16=308.5
hope this helps!