The vertices of a triangle are a(5, –4), b(7, 0), and c(1, –2). if the triangle is a right triangle, which vertex is the right angle?

Use mathematical induction to prove the statement is true for all positive integers n, or show why it is false. 1^2 + 4^2 + 7^2 + + (3n - 2)^2 = [n(6n^2-3n-1)/2]