"Volume of Triangular Frustum
'<hr /><div style = "max-width:120mm"><img style="height:60pt;" class="side" alt="triangular-frustum.png" src = "https://calcpad.eu/media/math/volume/triangular-frustum.png"></div>
'<p><b>Dimensions:</b></p>
'Bottom base
A = ?','B = ?','C = ?
'Top base
a = ?','b = B*a/A','c = C*a/A
'Height -'h = ?
'<!--
#if (A + B > C)*(B + C > A)*(C + A > B)
'<-->
'<p><b>Bottom base</b></p>
'Semiperimeter
p = 0.5*(A + B + C)
'Area (Heron equation)
A_1 = sqr(p*(p - A)*(p - B)*(p - C))
'<p><b>Top base</b></p>
'Semiperimeter
p = 0.5*(a + b + c)
'Area (Heron equation)
A_2 = sqr(p*(p - a)*(p - b)*(p - c)) 
'<p><b>Volume</b></p>
V = h/3*(A_1 + sqr(A_1*A_2) + A_2)
'<!--
#else
'<-->
'The sum of each two sides must be greater than the third.
'<!--
#end if
'<-->10	8	6	5	2