How can you find the volume of any triangular prism?

All prisms are uniformal shapes meaning that you only need to calculate the base are area and multiply it by the length for example:
Circular Prisms (cylinders)= (area of the base ) (height)=(πr^2)(h)
where h is the height and r is the radius
rectangular prisms = (area of the base) height =(ab) (c)
square prisms (cubes)= (area of the base) height=(S^2)(S)=S^3
where s is any side
triangular prisms =(area of the base) height =(0.5 b h) (l)=0.5 b h l
b is the base of your triangle and h is the height of the triangle and l is the length of the triangular prism

Multiply 9 and 67. then multiply 3 with 67. lastly the answer that you got for 9x67 is to be subtracted by the answer you got for 3x67