You should have posted that in "Software, Graphic Design", as it's realy a graphics related question.
If it's a fairly plain section, you can try the fill tool. Use the dropper to pick up the colour just next to the wedge and use it for the fill operation.
You can also sellect another section, press Ctrl + C to take a copy, then, sellect the area with your wedge shape and press Ctrl + V to paste your piece over.
You may need to do it as several paste operations if there are details you want to keep nearby.
You may want to apply some filters to hide the border of that area. Try the explode and blur operations. They can effeciently hide any discontinuity.
Electro, August 2011