Washington, D.C., formally the District of Columbia and commonly referred to as Washington, the District, or simply D.C., is the capital of the United States. The signing of the Residence Act on July 16, 1790, approved the creation of a capital district located along the Potomac River on the country's East Coast.
Now three of these sp 3 hybrid orbitals form sigma bonds by overlapping with three 1s orbitals of the three hydrogens and the remaining sp 3 hybrid orbital forms a sigma bond by overlapping with the sp 3 hybrid orbital of the other carbon which also has three Hydrogens bonded to it in the similar manner.
The combination of a sigma and a pi bond between the same two carbon atoms is a double bond. A double bond consists of a sigma bond (using hybrid orbitals) and a pi bond (using p orbitals). Another way of showing how two carbon atoms can form a double bond is indicated in the bottom (part c) of this diagram.