Approximately divide the region into 10 vertical strips, each with width of about 1. Next, estimate the y-coordinates of the top and bottom of each strip of this region. For example, the 1st strip stretches from approx. 2 1/4 at the bottom to approx. 2 1/4 at the top, so the total length of this strip is about 4 1/2. Since the area is (width)(height), and the width is approx. 1, the area is (4 1/2)(1) = 4 1/2.
2. Approximate the area of each of the remaining 9 strips.
3. Sum up your 10 approx. areas.
