Let's say I have a flat pattern of a rectangle. I sketch bend the two sides so it looks like a box with flages on each side pointing upward. My question is I want to bend half this rectangle with the two flanges on each side in a downard direction of 10DEG. So from the side view you will see the flanges dip down 10DEG from side so side.

I drew the sketch bend on the bottom of the rectangle in the middle perpendicular to the flanges then tried the sketch bend command and it did not work. Can someone get me in the right direction to make it possible for the 10DEG bend of the box.

Thank you.