$\mathrm{A},\mathrm{B},\mathrm{C}$ and $\mathrm{D}$ are any four points in the space. If $\left|\overrightarrow{\mathrm{AB}}\times \overrightarrow{\mathrm{CD}}+\overrightarrow{\mathrm{BC}}\times \overrightarrow{\mathrm{AD}}+\overrightarrow{\mathrm{CA}}\times \overrightarrow{\mathrm{BD}}\right|={\mathrm{\lambda }∆}_{\mathrm{ABC}} ,$ where $∆\mathrm{ABC}$ is the area of traingle $\mathrm{ABC},$ then $\mathrm{\lambda }$ is equal to