[above s+ below s+√ (above s × below s) ]*h /3 (can be used for four pyramids) [above area+below area+below root sign (above area× below area) ]× height ÷3?

(above s+ below s) *h/2 (cannot be used for four pyramids) (above area+below area) x height ÷2?

Extended data:

Similar triangles can get b/h 1=a/(h 1+h2), so h 1=bh2/(a-b).

v = A ^ 2(h 1+H2)/3-B ^ 2 * h 1/3

=h 1(a^2-b^2)/3+h2*a^2/3

=(a+b)*b*h2/3+a^2*h2/3

=(a^2+b^2+ab)*h2/3