Honestly, I'm not the best with this part, but I think you got it right
A complimentary angle is when the angle is 90 degrees, but the only 90 degree angle ( L ) is not an option. What you put for the other ones makes sense to me too, so I would say just go to the next one
What you need to do is do the formula of Area=1/2×Height (Base B +Base A) Base B is bottom Base A is the top then you divide by 2 In this case 1/2 ×8/1 ×(12+15)=108