1. The problem statement, all variables and given/known data A triangle has sides of length (n2+n+1), (2n+1) and (n2-1), where n > 1. (a) Explain why the side (n2+n+1) must be the longest side of the triangle (b) Show that the largest angle, θ , of the triangle is 120º. 2. Relevant equations In a triangle of sides a, b and c: a - b < c < a + b. 3. The attempt at a solution (a) n2+n+1 > 2n+1 n2-n > 0 n(n-1) > 0 Thus, n < 0, n > 1. n2+n+1 > n2-1 n+1 > -1 n > -2 I thought they would both give n > 1. I don't know what other way to show this is true. (b) I have no idea what to do here. I thought about vectors, but don't know where to go from there.