Let $\displaystyle y=9-x^2, y=0, x=0 $

Find a number h such that y=h would cut the region into two equal areas.

Now, I found out that the center of mass is (1,3.6), but how do I find the line? Do I just find the line that cut across (0,0) and (1,3.6)? The problem is the hint says that I need to integrate the area with respect to y, but I don't know how that is going to help.

Thanks!