I'm not sure if this is physics, but I thought I'd ask my question in case someone knows. In my effort to find the centroid of a cross section, I have a half-circle hole at the top of the shape. I know that the area is (r^2*pi)/2 and from the edge of cross-section to the center of the half-circle is 1.5 in. (The radius is .9 in.) How do I figure out the x and the y for the half-circle. Someone told me the x would be the distance 1.5 in. I'm not so sure about that. Thanks in advance if anyone knows what it is.