The triangle (9,9,4) is an isosceles triangle.


Let "a" be its angle opposite to the base of "4".


Then   = ;   =  = 0.2241 radians.


Hence, the angle  "a"  is  a = 2*0.2241 = 0.4482.


The number of such angles in full angle of   radians is   =  = 14.012,

or approximately 14.


Hence, the answer to the first question is 14 prisms.



Next, to find the volume of one such a prism, find first the area of its base.


To find the area of the  (9,9,4)-triangle, use the Heron's formula.


Semi-perimeter is  s =  =  = 11;

hence, the area is  A =  =  =  = 17.55 cubic inches.


The volume of one prism = 3*17.55 = 52.65 cubic inches,

and the volume of the 14 prisms is  14*52.65 = 737 cubic inches.    ANSWER