Simple, First lay out three matches to form a triangle. Then lay the other three from the center to the outside edge of the large triangle. You can do this from any point on the outside (large) triangle as long as it is three different points. This produces three smaller triangle within the larger one. Solution number two, And probably the solution in mind when the question was asked. Lay three matches to form a triangle. STACK the other three to form a three sided pyramid. from the points of the base up to center. You now have four sides that are all equilateral triangles. :)