Im having a hard time getting my head around this, any help would be much appreciated.

1. The problem statement, all variables and given/known data

Determine the position of the centroid and calculate the second moment of area about a horizontal axis passing through the centroid for the following sections shown. Attached is the image of the shape, including dimensions.

2. Relevant equations

A x Y(bar) = (A1 x Y1) + (A2 x Y2)

IX = Ix + Ah(squared) [Not sure if this equation is correct]

3. The attempt at a solution

I know Y(bar) to equal 40mm for the attached shape. However i dont know how to get from the y(bar) to the position of the centriod. The answer should be 862000.0mm, i just dont know how to get there, everything i try comes up with a different result.