An irregular tetrahedron has two opposite sides the same length
($a$ say) and the line joining their midpoints is perpendicular to
these two edges and is of length $b$. What is the volume of the
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice.