Given the area of object is 144cm² and the area of its image under an enlargement is 36cm². Find the scale factor of the enlargement

I think the 'enlargement' factor is     1/2

 

because the increase factor of the areas is   1/(2^2)   that is 1/4

 

The size has of course reduced - not enlarged.

To find the (linear) scale factor divide the square root of the area of the image under the enlargement by the square root of the area of the object.  (The word "enlargement" may be misleading!)

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