12. There is a batch of thin wooden strips of lengths $1, 2, 3, 4, 5, 6, 7, 8, 9, 10$ and 11 centimeters, and there are enough of each length. From these, select 3 strips appropriately as three sides to form a triangle. If the base is specified to be 11 centimeters long, how many different triangles can you form?
12. 【Solution】In any triangle, the sum of the lengths of any two sides is greater than the length of the remaining side. In this problem, let the base of the triangle be 11 cm, and the other two sides be $\mathrm{a}$ and $\mathrm{b}$, respectively. Therefore, we must have $11 < a + b$. Additionally, for definiteness, let $a \leqslant 6$. Thus, the possible values of $(a, b)$ are $(11,11); (10,10), (10,11); (9,9), (9,10), (9,11); (8,8), (8,9), (8,10), (8,11); (7,7), (7,8), (7,9), (7,10), (7,11); (6,6), (6,7), (6,8), (6,9), (6,10), (6,11); (5,7), (5,8), (5,9), (5,10), (5,11); (4,8), (4,9), (4,10), (4,11); (3,9), (3,10), (3,11); (2,10), (2,11)$; $(1,11)$, a total of 36 combinations.

Answer: 36 different triangles can be formed.