PowerPoint 2013 now makes it easy for you to combine a set of shapes into a single shape so that you can work with it as one item on the page. This means that you can animate it easily rather than having to make sure that each individual component in the drawing is selected. When you choose the Merge Shapes tool on the Drawing Tools Format tab, you can select Union, Combine, Fragment, Intersect, and Subtract to create just the kind of effect you want from the resulting merged shape.
Select the shapes that you want to merge.
Click the Drawing Tools Format tab.
In the Insert Shapes group, click Merge Shapes.
Point to a merge option to preview it on the slide; click the one that you want to apply.