We know the ratio in between.

First:

Get the size of the first CRect.

Second:

Get the Center Point of the first CRect.

Third:

Using the ratio in between to get the size of the second CRect correspondingly and cut x,y of the second size in half and substract Center Point by it respectively will give you the top-left point of the second.

Fourth:

Using the CRect( POINT point, SIZE size )to construct the second CRect.

Regards

W.Yinan