Different block size in block matrix

Question

I am following a book and having trouble understanding.

so from Section 6.6.2 page 496, i have

A = NxN matrix
b = Nx1 vector
c = Nx1 vector

from Section 14.3.2 I have,

And this is what author says,

so now q = \begin{bmatrix} -c_0\; \\ b_0\; \end{bmatrix}

lets assume from section 6.6.2,

A = 3x3 matrix
b = 3x1 vector
c = 3x1 vector

so $c_0\; = -2b^TA$ = 1x3 matrix

$b_0\;$ = \begin{bmatrix} b\; \\ c - b\; \end{bmatrix} = 6x1 matrix

so for q upper block has 3 columns while lower has 1. what wrong am i doing ? And same thing is happening with M.