How to round the corners of several rectangles equally?

Aiming for a consistent look, you like to apply the same round corners for the picture as for the text box below. This seems logical, but it’s not so obvious in MS Office…

Both picture and text box are Rounded Rectangles: one with picture fill and the other one used as a text box.

When you select one Rounded Rectangle, a yellow diamond handle appears in the upper left. By dragging this handle, you can adjust the rounding of the corner.

But when both Rounded Rectangles are selected, no yellow diamond handles show up. In other words, it is not possible to round the corners of both shapes simultaneously.

Nevertheless, it is possible to resize several shapes, change the fill and the outline, the shape, the text fill, the position, the text wrapping,… of several shapes simultaneously. So why is it not possible in this case? That’s a shame.

If you want several Rounded Rectangles with the same size, copying one shape with the desired curvature is a good solution.
But when you resize a copied Rounded Rectangle, the radius of the corners does not remain the same. So this is not a solution for the given example, of which the text box is a lot lower than the photo frame.

Is there a way to resize a Rounded Rectangle without the corners changing?

Knowing the exact degree of the rounding would be a great help, as it would enable you to apply the same radius to all round corners, but such indicator does not pop up (cfr. the Adobe suite).

Trying to imitate the same curving by sight seems the only way to get equally rounded corners. It does not take much effort to do this once, but imagine this rounded corners are part of your corporate identity… adjusting each rectangle individually would take up a lot of time. Besides, this working method gives you no control on the exact degree of curve so consistency is virtually impossible.

Feel free to share any insight on this problem or another workaround!

Based on MS Office 2013