Well, this is how I do it.
Multiply 4 and 10 and get the area of the whole thing. Answer is 40.
Then, multiply 3 and 5. (I got 5 from subtracting 2 and 3 from 10). This gives me the area of the missing piece. Answer is 15.
Lastly, I subracted. 40 - 15. Gave me 35.
My final answer I got is 35. I hope my answer is correct! I hope this helped!
