I have a matrix $K_{3x3}$ that I would like to convert into a matrix of the form: $$ L' = \begin{bmatrix} a & 0 & 0 \\ b & 1 & 0 \\ c & 0 & 1 \\ \end{bmatrix} $$ by multiplying it with a series of Givens rotation matrices: $$ L'KLG_1G_2...G_n $$ Is this at all possible? If so what sequence of Givens rotations annihilates the correct elements?
Is there some other way I can uniquely decompose: $$ K = L'R $$ where R is an orthogonal matrix?