Answer
Doubles the $x$-coordinates
Work Step by Step
The matrix of the initial triangle's coordinates is:
$B=\begin{bmatrix}0&2&2\\0&0&-4\end{bmatrix}$
Consider matrix $A$:
$A=\begin{bmatrix}2&0\\0&1\end{bmatrix}$
Compute $AB$:
$AB=\begin{bmatrix}2&0\\0&1\end{bmatrix}\begin{bmatrix}0&2&2\\0&0&-4\end{bmatrix}$
$=\begin{bmatrix}0+0&4+0&4+0\\0+0&0+0&0-4\end{bmatrix}$
$=\begin{bmatrix}0&4&4\\0&0&-4\end{bmatrix}$
We notice that the new triangle has double $x$-coordinates in comparison with the initial triangle.
