Answer: Choice D. No, because 3+5 < 9
Explanation: Refer to the triangle inequality theorem
This theorem states: a triangle is only possible if adding any two sides yields a sum larger than the third side.
In terms of inequalities, we need all 3 shown below to be true.
In this case, the triangle has sides a = 3, b = 5, c = 9
Notice how a+b = 3+5 = 8 is not larger than c = 9. Therefore, the inequality a+b > c is false to determine a triangle is not possible with these side lengths. Grab 3 pieces of string with lengths 3 inches, 5 inches, and 9 inches to try it out for yourself. The 3 inch and 5 inch pieces come up too short compared to the 9 inch side.