How do you find the # of sigma and pi bonds using a Lewis dot structure

Every single bond is a sigma bond.
A double bond contains 1 sigma bond and 1 pi bond.
A triple bond contains 1 sigma bond and 2 pi bonds.
For example, in acetylene, H-C≡C-H, the sigma bond is formed by the head-on overlap of two sp orbitals. The pi bonds are formed by the side-on overlap of 2p orbitals.