



 
Hi there. When you have similar shapes and the ratio of the linear dimensions is x, then the ratio of the area dimensions is x^{2}. What I mean is this: The side length of the second pentagon is 28. So the ratio of the linear dimensions is 28/12 = 7/3. A = (248) (7/3)^{2}. You can also calculate it the longhand way. See the following examples: Or just type pentagon into the Quick Search. Cheers,  


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