10 triangle with vertices:

(6,18) (11,20) (16,19)
(16,19) (6,18) (8,16)
(10,14) (16,19) (8,16)
(5,13) (8,16) (10,14)
(15,12) (10,14) (5,13)
(9,11) (5,13) (15,12)
(13,9) (15,12) (9,11)
(7,8) (9,11) (13,9)
(13,9) (7,8) (14,4)
(13,9) (14,4) (19,3)