Question 957551
she starts at 4.8 by 6.2 and it now measures 16.8 by 21.7


the vertical to horizontal ratio is 4.8 / 6.2 = .7741935484


the vertical scale factor is 16.8 / 4.8 = 3.5


the horizontal scale factor is 21.7 / 6.2 = 3.5


since both scale factors are the same, the enlarged image has the same proportions as the original image.


the vertical to horizontal ratio is 16.8 / 21.7 = .7741935484


she reduces the image to 7.2 by 9.3


the vertical scale factor is 7.2 / 16.8 = .4285714286


the horizontal scale factor is 9.3 / 21.7 = .4285714286


since both scale factors are the same, the reduced image has the same proportions as the original image and the enlarged image.


the vertical to horizontal ratio is 7.2 / 9.3 = .7741935484


the original image is 4.8 by 6.2


the final image is 7.2 by 9.3


the overall change in the size of the image is an enlargement.


the overall scale factor is:


vertical from 4.8 to 7.2 = scale factor of 1.5


horizontal from 6.2 to 9.3 = scale factor of 1.5


the scale factor for vertical and horizontal is the same so the image is still in proportion.


the original image is 4.8 by 6.2


the modified image is 10.2 by 6.2


the vertical scale factor is 10.2 / 4.8 = 2.125


the horizontal scale factor is 6.2 / 6.2 = 1


the resulting picture will not be a true enlargement because the picture is not in proportion any longer.


a true enlargement only changes the size.


it doesn't change any of the relationships between the parts.


that's my understanding.


the two figures are geometrically similar if they are proportional.


that means the size is changed but not the shape.


the last example changes the shape so it is not a true enlargeement.