Model with simple frustrum - volume calculation wrong I make a lot of models that involve pyramidal frustrums (transition of a rectangular section to another rectangular section, linearly). Rather than use the measured value calculated by Creo, I thought I'd have a go at calculating the volume directly from the dimensions.When I check my calculations, the volume calculated directly from the dimensions differs from the Creo analysis result.I minimized the accuracy value, but still get the exact same result.Here are my simple valuesBase rectangle: 5 X 3 -> Base area: 15Top rectangle: 4 X 2 -> Top area: 8Height: 1Frustrum of a pyramid volume is Volume = ( Area Base + Area Top + SQRT ( Area Base * Area Top ) ) * Height / 3 = 11.3182Creo, on the other hand, gives a volume of 11.3333.Anyone have any insights into this? This is simple shape, and kind of scares me about what might be happening with more complicated geometry.