  In this paper we study areas (called p-areas) and volumes for parametric
surfaces in the 3D-Heisenberg group $\mathbb{H}_1$, which is considered as a
flat model of pseudo-hermitian manifolds. We derive the formulas of p-areas and
volumes for parametric surfaces in $\mathbb{H}_1$ and show that the classical
result of Pappus-Guldin theorems for surface areas and volumes hold if the
surfaces satisfy some geometric properties. Some examples are also provided,
including the surfaces with constant p-mean curvatures.
