linear algebra: orthogonal basis

Let W be the column space of A=[ 1 3 1 -1; 2 6 0 1; 4 12 2 -1]. Find an orthogonal basis for W.

I got {[1; 2; 4], [1; 0; 2]} as the column space(W) and consequently {[1; 2; 4], [4/7, -6/7, 2/7]} as the orthogonal basis. Am I right? I basically row reduced A and since the leading 1's were in the first and third column, I looked in A for those columns and those two columns from A become the column space.

Question

linear algebra: orthogonal basis

Let W be the column space of A=[ 1 3 1 -1; 2 6 0 1; 4 12 2 -1]. Find an orthogonal basis for W.

I got {[1; 2; 4], [1; 0; 2]} as the column space(W) and consequently {[1; 2; 4], [4/7, -6/7, 2/7]} as the orthogonal basis. Am I right? I basically row reduced A and since the leading 1's were in the first and third column, I looked in A for those columns and those two columns from A become the column space.