[ REQ 6969]: calculating volume

[amoser at science.uottawa.ca]

hello
i am looking information on calculating volume any "irregular"
antiprism based on the coordinates of the eight corners, and thus,
generalize for any 6-faced shape.  
for example:
A (1.89, 6.39, 4.63)
B(0.32, 5.18, 6.25)
C(0.99, 2.08, 5.66)
D(2.57, 3.22, 4.04)
A'(3.73, 6.41, 6.19)
B'(2.75, 4.21, 7.27)
C'(3.91, 2.11, 6.15)
D'(4.91, 4.38, 5.00)

or can u direct me to someone who might be of help.

thanx
 arvin