So, According to the image you send me we have two shapes, one original and a scaled image.
In order to calculate the scale factor you would have to compare the sides by finding the ratios.
So, the original has one side of 6.9 ft and 3 ft, and the scaled image of 2.3 ft and 1 ft.
Therefore, if we divide the side of 6.9 ft of the original image to the side of 2.3 ft of the scaled image we get the following:
side of 6.9 ft/side of 2.3 ft=3
and if we divide the side of 3 ft of the original image to the side of 1 ft of the scaled image we get the following:
side of 3 ft/side of 1 ft=3
Therefore, the scale factor that was used to create the scaled image is 3