I disagree with Bert Sercu. In fact, you CAN change the shape of what SmartArt has given you into another shape from Microsoft Word(if that is what you mean), and it is very simple to do. You just click the shape that you wish to change, and (under the "SmartArt tools" section), you click the Format tab (if you see options like "Shape Fill", "Shape Outline","Text Effects" etc then you are in the place I am speaking of). Go to the far left of the screen and go to the section called Shapes. There, you should see items such as Edit in 2-D, Larger, Smaller, and Change Shape, which is a drop down menu. You click Change Shape and when the drop down menu appears, you chose the shape you are wishing for(if it is there).
You can do the same thing in Microsoft PowerPoint, like Bert Sercu said. Just right click the PowerPoint and a drop down menu should appear. Go down until you see the word layout and chose any layout that has those six things in the middle. chose the green arrow out of those six items, chose the chart you want, and repeat the instructions above to create a different shape.
I know the directions are long even though the solution takes little time, but I did this in case people, like me, have a hard time reading directions and need to see it visually or read/hear it step-by-step.