Question

Given the side lengths below, determine which triangle is not possible.

(A) 4, 5, 6

(B) 4, 3, 6

(C) 3, 4, 5

(D) 3, 3, 6

Answer 1

(D) 3, 3, 6

Explanation:

The triangle inequality says the sum of the shortest two legs must be longer than the longest. In the case of {3, 3, 6}, the sum is exactly equal to the longest, so the "triangle" will look like a line segment and have zero height and zero area,

Some authors describing the triangle inequality find that to be an acceptable condition. Apparently the author of this question does not.