(Higher SQA) maths - Finding the area between a curve and 2 lines ?

Not sure if I can explain this well without an image, but I am struggling to figure out how to find the area enclosed by a curve and TWO lines.
I can do every other question apart from these with no problem; normally just finding the integral of upper - lower bound to the limits found by using y1 = y2. But how do you do that with 3 functions (e.g a curve with 2 horizontal lines inside it enclosing an area if that makes sense)? I can't seem to get it no matter how hard I try! It's probably really easy and I'm overthinking it tbh. I will be asking my teacher for help, but I figured someone here might be able to help too.