In the figure, three small circles have a radius of 4. Another large circle is drawn, so that all four circles are enclosed in an equilateral triangle. Find the side length of the equilateral triangle.

If PN = 4 than AN = 12 ( see diagram )

If AN = 12 than AM = 36

If AM = 36 than the side AB = AM / sin(60°) = 41.56921938

41.56921938 / sqrt(3) = 24

The side length of the equilateral triangle is 24*sqrt(3)