So we use the right boundary of each of these subdivisions to define the height. So our right boundary is when x equals four for this first section. What is f of four? It's eight. So we're gonna use that as the height of this first rectangle that's approximating the area for this part of the curve. Similarly, for this second one, since we're using a right Riemann sum, we use the value of the function at the right boundary, the right boundary seven. So the value of the function is three.