St John Altarpiece (Memling) St John Altarpiece (Memling) The St John Altarpiece (sometimes the Triptych of the two Saints John or the Triptych of St John the Baptist and St John the Evangelist) is a large oil-on-oak hinged-triptych altarpiece completed around 1479 by the Early Netherlandish master painter Hans Memling. It was commissioned in the mid-1470s in Bruges for the Old St. John's Hospital ("Sint-Janshospitaal") during the building of a new apse. It is signed and dated 1479 on the original frame – its date of installation – and is today at the hospital in the Memling museum. The altarpiece consists of five paintings
Hinged dissection Hinged dissection A hinged dissection, also known as a swing-hinged dissection or Dudeney dissection, is a kind of geometric dissection in which all of the pieces are connected into a chain by "hinged" points, such that the rearrangement from one figure to another can be carried out by swinging the chain continuously, without severing any of the connections. Typically, it is assumed that the pieces are allowed to overlap in the folding and unfolding process; this is sometimes called the "wobbly-hinged" model of hinged dissection. The concept of hinged dissections was popularised by the author of mathematical puzzles, Henry Dudeney.