Represent the dots by numbers 1 to 25 in rows from left to right 1 to 5, 6 to 10, etc. Join 1 to 5; join 1, 6 and 11; join 5, 10 and 15; join 11 and 12; join 14 and 15; join 12 and 23; join 14 and 23. Dots enclosed are: 7, 8, 9, 13 and 18. Dots outside are: 16, 17, 19, 20, 21, 22, 24, 25.