The perimeter of the isosceles triangle is 12 inches.
For a triangle to have one interior (closed figure), the sum of two of the sides of a triangle has to be greater than the other side. In this problem, we have two cases. Case one, the sides are 2, 2, and 5. Case two, the sides are 5, 5, and 2. Case one is impossible because of 2+2 = 4 which is less than 5. Therefore, the perimeter would be the sum of all the sides, 5+5+2 = 12 inches.