Carlota has strips with the measures 3, 4, 5, 6, and 12.

The possible number of triangles are 4 and their measures are

1. 3, 4, 5

2. 3, 5, 6

3. 3, 4, 6

4. 4, 5, 6

The perimeter of the triangle with the measures 3, 4, and 5 is 12.

The perimeter of the triangle with the measures 3, 5, and 6 is 14.

The perimeter of the triangle with the measures 3, 4, and 6 is 13.

The perimeter of the triangle with the measures 4, 5, and 6 is 15.

Since the perimeters  12 and 15 are divisible by 3.Carlota can make 2 triangles that have a perimeter that is dividible by 3.