The total number of $\mathrm{\pi }$-bonds present in a single plane in the compound ${\mathrm{C}}_3 {\mathrm{S}}_2$is:

The total number of $\mathrm{\pi }$-bonds present in a single plane in the compound ${\mathrm{C}}_3 {\mathrm{S}}_2$ (Carbon sub sulfide) is 2

$\mathrm{\pi }$ bonds are created when atomic orbitals cross one another perpendicular to the internuclear axis in a sideways positive (same phase) direction. When bonds are formed, the atomic orbital axes are parallel to one another, however when they overlap, they are perpendicular to the internuclear axis.