Henry Ernest Dudeney/Modern Puzzles/213 - The Six Pennies/Solution

Modern Puzzles by Henry Ernest Dudeney: $213$

Lay six pennies on the table, and arrange them as shown by the $6$ white circles in the diagram,

so that a seventh penny can be dropped into the centre and touch each of the other $6$.

It is required to get it exact, without any dependence on the eye.

In this case it is not allowed to lift any penny off the table, nor can any measuring or marking be employed.

However, you are allowed to slide the pennies after they have been placed on the table.

You require only the six pennies.

First lay out the pennies as follows, noting that they have been numbered in order to identify them.

Move penny $6$ to touch $4$ and $5$:

Move penny $5$ to touch $2$ and $3$:

Finally, move penny $3$ to touch $5$ and $6$ as indicated by the dotted circle in the diagram above.