The dilation of a figure with a scale fator k means that the distance of each point of the image from the center of dilation will be k times the distance of the original figure from the center of dilation.
Also the length of each two points of the image is k times the length of each two points of the original figure.
From the given figure, the vertices of the original triangle are (-3, 3), (6, 6) and (3, 9).
The vertices of the
image of this figure after a dilation with a scale factor of 1/3 centered at the origin is given by

Therefore, the verties of the image of this figure after a dilation with a scale factor of 1/3 centered at the origin are (-1, 1), (2, 2) and (1, 3).