So if we look at our first rectangle right over here, actually let's just first appreciate we have split up the interval from x equals negative one to x equals two into three equal sections. And then each of them have a width of one. So if we wanted a better approximation, we could do more sections or more rectangles. But let's just see how we would compute this. Well, the width of each of these is one. The height is based on the value of the function at the midpoint. The midpoint here is negative 1 1 2.