2 questions about angles in polygons

The following hormone had their receptors in the cell membrane except a-insulin b-tsh c-gh d- cortisol

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]

Zack and tia played chess for 50 min they put the chessboard away at 11: 20 when did they start