## Task Condition

Calculate the volume of the tetrahedron with vertices at points $A_{1}, A_{2}, A_{3}, A_{4_{\text {and }}}$ its height dropped from vertex $A_{4 \text { to the face }} A_{1} A_{2} A_{3}$.

$A_{1}(1 ; 2 ; 0)$

$A_{2}(3 ; 0 ;-3)$

$A_{3}(5 ; 2 ; 6)$

$A_{4}(8 ; 4 ;-9)$