Why did we apply all those extrudes to the sides of our 3D model? The reason for so many extrudes is so that, at the end, we have four small planes at the sides of our seat. Using those planes, we will be able to use additional extrudes as a way to quickly create all the other parts of our chair.
Do you want to see how easy it is will be to create the legs for the chair?
If you rotate the model using either the Navigation Widget or the middle mouse button, you will be able to move the view to the bottom of your seat. At this point, you should select all four small faces in the corners of the model.
With that faces ...