



 
Mady, The general expression is (Base area) times (height). To find base area triangle area = a x b x sin(C)/2 where a,b are the lengths of two edges, C the angle between them. If one angle of the base triangle is a right angle the area is just half the product of the neighboring sides, because sin(90 degrees) = 1 If you know all three edges and no angles of a triangle, you can use the cosine law a^{2} = b^{2} + c^{2} 2bc cos A to find A, or more directly use Heron's formula Good Hunting! Mady, I want to add a footnote to RD's response. The expression volume = (Base area) times (height) is true for any prism not just triangular prisms. The expression also holds true if the prism is not a right prism as long as the height is the distance between the congruent, parallel polygons. Harley  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 