Let a vault consist of two equal half-Cylinders of length and diameter which intersect at
Right Angles so that the lines of their intersections (the ``groins'') terminate in the
Vertices of a Square. Then the Surface Area of the vault is given by

**References**

Lines, L. *Solid Geometry.* New York: Dover, pp. 112-113, 1965.

© 1996-9

1999-05-26