Homework: Hessenberg, Givens matrix calculations QR

Question

I have been trying to figure out for the past 2 hours and I have to say I give up. My last resort is that maybe someone will have time to explain this to me.

The task is to calculate matrix A= \begin{bmatrix} 12 & 65 & 65 \\ 3 & 13 & 0 \\ -4 & 0 & 13 \end{bmatrix}

1. Into Hessenberg matrix A'.
2. Find QR factorization for A' matrix using Givens rotations.

Thanks in advance!