Is it possible to build a triangle with side lengths of 3 3 and 9.?

No, it is not possible to build a triangle with side lengths of 3, 3, and 9. According to the triangle inequality theorem, the sum of the lengths of any two sides must be greater than the length of the third side. In this case, 3 + 3 is not greater than 9, so these side lengths cannot form a triangle.