Pentiles-2

The Grid



The Set: 4 pentiles



The Set: 1-3 pentiles



If the complete 1-3 set is used, or included, one additional single pentile is needed to complete the last 3-pentile hexagon.
In that case, the total 1-3 set contains 10 hexagons, for a base-4 triangle, and the total 1-4 set contains 42 hexagons, which is a base-9 triangle with 3 holes.



The Idea
Here's, for one, a base-4 triangle with the 1-3 set and the additional single pentile.



And here, for two, a base-9 triangle with the 1-4 set and the additional single pentile.



Pentiles-2 © MindSports.