Henry Ernest Dudeney/Puzzles and Curious Problems/206 - The Triangular Plantation

by : $206$

 * The Triangular Plantation
 * A man had a plantation of twenty-one trees set out in the triangular form shown in the diagram.


 * Dudeney-Puzzles-and-Curious-Problems-206.png


 * If he wished to enclose a triangular piece of ground with a tree at each of the three angles,
 * how may different ways of doing it are there from which he might select?


 * The dotted lines show three ways of doing it.
 * How many are there altogether?


 * This is just one of those puzzles that call for the exercise of a little cunning in the solving.