Forum Discussion
Volume of Triangular Prism excel formula
Let's say you enter the values for a, b, c and h in B1, B2, B3 and B4, respectively.
In another cell, say B5, enter the formula
=B4/4*SQRT((B1+B2+B3)*(B2+B3-B1)*(B3+B1-B2)*(B1+B2-B3))
or
=B4/4*SQRT(-B1^2+2*(B1*B2)^2+2*(B1*B3)^2-B2^2+2*(B2*B3)^2-B3^2)
=B4/4*SQRT(-B1^2+2*(B1*B2)^2+2*(B1*B3)^2-B2^2+2*(B2*B3)^2-B3^2)
Incorrect. Three typos and a translation mistake. Errata:
=B4/4*SQRT(-(B1^4)+2*(B1*B2)^2+2*(B1*B3)^2-B2^4+2*(B2*B3)^2-B3^4)
Note: In Excel, -B1^4 is parsed as (-B1)^4, which is always positive. But in math, it is parsed as -(B1^4), which is always negative.
PS.... In selecting a, b and c, we must avoid SQRT returning #NUM because its parameter is negative. An online calculate [*] specifies the following requirements:
a+b > c
a+c > b
b+c > aOne set of values that meets those conditions:
a: 123
b: 456
c: 543[*] online calculator (click here)
