Answer:
Yes he is correct
Explanation:
Given a triangle ABC, the sum of the lengths of any two sides of the triangle is greater than the length of the third side. In the words of Euclid: In any triangle two sides taken together in any manner are greater than the remaining one.
If we add the two sides 12 and 18 we get 30 so the third side must be greater than 30. He said greater than 6 so he is right too